How do I set better boundaries with my brother?

For context: I have severe contamination OCD and part of that is with feet (I also had trauma as a child concerning feet.) I can't be near feet or touch something that someone else's feet have touched without getting disgusted (the only exception being my own when they are clean or my husband's after we shower, and that's still hard sometimes.) I also have fibromyalgia (chronic pain/fatigue) that is affected by my OCD because the stress sets off my nerve issues, so every time my OCD is triggered, I am put into extreme pain sometimes for days. I have been bedridden for months at a time in the past. I know the whole thing with learning to live with OCD is ERP therapy, but I have deeper psychological issues (other forms of ocd and ptsd) than just my contamination OCD that I am working on, that have been extremely difficult to manage. The contamination ocd is the least of my worries right now, but I need to be able to feel safe and comfortable so that I can keep working on my issues.

My younger brother (21m) has lived with me (28f) for a couple years because our family situation is super messed up and our parents suck. He has nowhere else to live as far as I know. When he first moved in with me, I had my own small 1 bedroom apartment and a job and was going to college, but I kept getting sick and couldnt keep up with anything so my apartment (and my life) was just chaos, especially after it became cramped when my brother moved in. Eventually I got so sick that I failed out of school and lost my job because of absences because I was bedridden for about a year. My brother and I coexisted then because I made sure he had a space he felt like was his even though the space was small, and I had my room. So it got really dirty because I was too sick to clean and it was cramped, but I mostly just stayed in my bed. My ocd was still bad then, but my brother didnt notice it as much because I was too sick to care and was just surviving.

Then my fiance and I decided to buy a home together, that was much bigger, which changed my life. My fiance works and pays all the bills, and Im basically a housewife. The increase in space and decrease in stress has helped me heal and get better, and now im moving around more and can take care of myself amd my home a lot better. I still get too sick sometimes to keep up with chores, but I do my best and my husband helps sometimes by cooking dinner or doing quick basic chores like taking out the trash.

I prefer my home to be clean, and Im constantly striving to achieve that because thats when I am most comfortable and have the least amount of pain, and my fiance likes to have a clean home too. Everything in my house runs in a system and has rules so that things dont get dirty so quickly, and so that I dont have to clean so often. I have a lot of little pet peeves and rules, but my fiance happily follows along with them and they don't bother him because he respects my boundaries and cares about me being comfortable. My brother however, has been a jerk about a lot of it.

He has his own bedroom in my house and lives here rent-free. He hasn't held down a job without giving up and quitting, so I've paid basically all his bills for the last year.

He has told me that I'm hard to live with because of my OCD, and we've fought a lot about it. He's told me that he misses the way I was before we moved. But he doesn't clean up after himself in the kitchen and is always leaving dirty dishes and crumbs on the counters which then makes it hard for me to use the kitchen myself. He didn't want to use my laundry machine the way I told him to (even though both our washer and dryer have already broke once and we had to replace them, which was expensive), and we got in a fight about it. He is always rolling his eyes at me and getting annoyed when I ask him to do or not to do something. I have to ask him multiple times to get anything done. For example, taking out the trash is supposed to be his responsibility, but it's constantly getting overfilled and my fiance then has to do it. I've worked so hard over the past year to keep my home clean and into a state that isnt pure chaos despite my disabilities, but my brother makes that so hard sometimes.

Today we had a major argument because I asked him to not put his feet on my reading nook, which he often does and he knows it bothers me. And it took me a long time to finally confront him about it (because I avoid conflict both because I dont want to start ruminating about it like I am now and then get sick again, and also because I have ptsd from being physically abused by my ex. Also, I already knew how he was going to react because he does that same passive aggressive behavior every time I confront him about anything. He makes it seem like Im crazy or something, and then runs off and Im left trembling from the anxiety.) But I havent been able to use my reading nook for over a month because he keeps putting his feet on it and I dont have the energy to clean it and so I cant bring myself to sit there even though I'd like to. So I decided I finally had to confront him.

This is exactly how the conversation went:

Me: "Hey, can you please not put your feet on the furniture?" Him: "I just put these socks on, so they are clean." Me: "Yeah but I have ocd that you are affecting" Him: "What, so I cant be comfortable?" Me: "What about my comfort? You live in my house" Him: "ok ill just stay in my room all day and never come out" Me "you dont have to do that, just dont put your feet on the furniture. If you dont like my rules I dont know what to tell you. I dont have to defend myself or explain myself to you."

Then he just got up and went into his room and closed the door, and then later left the house. As he was leaving I said "hey I know you are mad at me. But I feel like you really dont respect me sometimes and everything that we've done for you. It really hurts my feelings." He left without saying anything.

I sent him this text: "I hope you know that I love you and care about you and I do want you here. But you need to respect my boundaries and my house rules. It doesnt matter if you think they are unreasonable, because it is my house. (My fiance) and I have worked hard to get here. I know youve said that im hard to live with because of my ocd. You could move out if you dont like it here. I cant. And I deserve to have a home where I can feel comfortable and safe even if you dont understand. I am going to get an ottoman that is meant for feet so that you can put your feet up on something if youd like, just not the furniture where id like to sit too. Plenty of people dont want feet on their furniture. Its not an unreasonable request. Ive been meaning to say these things to you for a long time but havent been able to for fear that youd react like this. But thats not the way things should be. You live in my house rent free. You realize that you have an entire room that you do whatever you want with in my home? You need to respect my boundaries and rules regardless if you agree with them or not. Im not trying to fight and I love you but there needs to be ground rules for you being here and you need to respect me because I dont want to have a fight or feel bad every time I need to set a rule or boundary."

And he just texted "ok boundaries respected" and then came back later and closed himself in his room and we havent spoken in like a day.

I have a soft spot for him, and I cant help but feel like I was too harsh. He has depression and has told me he's felt apathetic about life. I have been a lot more strict than I used to be, but that's because I need my home to be a safe space and I've gotten better enough to make that happen. I've told him in the past that I dont mind if he lives with me forever as long as he pulls his own weight and respects my space. I feel somewhat responsible for him because I convinced him to move in with me because our father was abusing him. But at the same time, I feel like he's being ungrateful and that I'm being taken advantage of. It is ruining our relationship, and he's the only family I have. I dont know what to do.

TLDR: My brother lives in my house rent-free and keeps putting his feet on my furniture, despite knowing that it bothers me because I have OCD. I asked him to stop putting his feet on my furniture today, and it turned into a major argument.