AIO when I lost it over my BIL trying to take “my” car AGAIN

Important background:

1. The car isn’t actually mine, it’s my husbands. He bought it a couple of months before we met. We’ve been married for almost 11 years and the car is a 2014. It only has 92000 miles on it and is perfectly mechanically sound.
2. I have had my license for less than a year. My therapist diagnosed me with a phobia of driving and it took over a year of exposure therapy with step by step lessons and therapy sessions for me to pass my test and start driving daily. It’s been amazing to finally be able to drive and do so many things I have never been able to do.
3. My brother in law is extremely entitled. Everything he has is his and everything my husband has is also his OR he finds a way to talk trash about whatever it is my husband has. Example: when we bought our first house he told us we needed to clean out our garage because he was going to buy a go cart and store it in our garage. I told him no, that once our garage was clean it was only for my husband’s car. He then said we needed to clean out our shed for his go cart then. I again told him absolutely not. That’s just one example.
4. every single time I’ve seen BIL since getting my license he has made fun of me about my driving, what I am or am not comfortable with or something of the sort. My husband never says anything.

Now here is the problem. My husband has a 2019 of his “dream car” and that’s his daily driver. The understanding has been that once I got my license the 2014 vehicle would be mine to drive and it’s even the car I did all my therapy in. I also do all maintenance of the vehicle.

My BIL KEEPS trying to take it from me. During my therapy he yelled at me and told me I had to give him the car for my MIL to drive while WE were paying to fix her car. I told him no. When I got angry at him and told my husband to deal with him, he said he did.

Not too long after my BIL said he needed my car because his was going into the shop and he needed a car to get to work. I told him no in front of my husband who told his brother “he would agree with whatever I said” instead of just telling his brother no. So his brother continued to tell me how bad he needed my car. I told him no.

Tonight my BIL calls my husband and tells him that he needs my car to teach my niece to drive because mine has the most miles (not true his car definitely has more). My husband laughed his ass off. Told him to let my niece drive his instead to which BIL of course insisted on mine and husband deflected to telling them to do a driving school. When the call ended I was pissed. I tell husband I don’t feel comfortable teaching anyone how to drive. He tells me they just wanted to come take my car not for me to do anything which for some reason pissed me off more.

This is the THIRD time he’s tried to TAKE my car. When I called my BIL entitled my husband told me he wasn’t being entitled and I was making a big deal out of nothing. BIL was just making a funny joke.

I didn’t speak much after that and husband started pressing me asking why I was upset.

I lost it crying trying to explain that I’m tired of being the butt of his brothers stupid jokes and him constantly trying to take my car when I worked so f-ing hard to have the ability to even drive it. I’m so sick of MY accomplishments and needs being disposable and undermined. My husband maintains I’m overreacting because ultimately he talked his brother out of taking my car and it’s not a big deal. I told him he never defends me with his brother and I’m so tired of it.

AIO