I (22f) am struggling to explain my emotional needs to my bf (23m)

Ive been with my boyfriend for about 3 years now. We’ve known each other for about 12 years and were very close in the past before we started dating. He’s been in relationships before, but this is really my first real and committed relationship.

Ive always dealt with anxiety and depression for as long as I can remember. My parents don’t believe in mental health, so it’s only been recent that I’ve been able to try and get help now that I’m in charge of my own healthcare. I’m currently on an antidepressant and an anti anxiety medication. I also just asked that my gyno change my oral birth control because the most recent one they put me on I gained 40 pounds in only about 3-4 months and calorie deficits and increased exercise haven’t been budging my weight which has really increased my mental health issues.

Hes always been very patient with me and understands that I have mental health issues. However, I’ve been stuck in a pretty bad rutt for the past 2-3 months. It’s one of the worst phases Ive had. Admittedly, I’ve been distancing from him and pushing him away and I don’t know why. I love him. I honestly want to marry him. But I constantly feel over stimulated and like i’m in fight or flight. When he asks to hang out, the first thing he wants to do is hug and kiss all over me. Not in a sexual way but just in a miss you way. But recently it’s been sending me over the edge. I feel like all I want to do is lay in bed in a cocoon and not be touched or talked to and that’s not fair to him which I know.

I tried talking to him about how I’m feeling yesterday but I was really struggling to put into words what I’m feeling. I can tell it’s starting to impact him this time. I don’t remember that last time we had sex and when he tries to initiate it I have such a hard time trying to relax that my body starts to tense and I just can’t do it. He’s never pushed and will move on if I say no, but I’m afraid he’s going to seek other means of relief which makes me sadder.

I don’t know how to tell him “i’m overstimulated all the time. i love you but when you touch me it makes me so much more tense and i feel like i can’t breathe and I dont know what to do” without it sounding absolutely awful.

If you’ve been in a similar situation, do you have advice on how I can better initiate this conversation? Does anyone have any advice as well as to what helps them relax when they feel overloaded?