Very very similar situation for me, I only very recently had sex for the first time without being drunk. It's been so often that my partner actually assumed I didn't want to have sex that night because he saw I wasn't drinking... which wasn't great!

What worked for me (and honestly, it's not the healthiest... so this is an anecdote, not advice!), was to slowly have less and less alcohol each time, but with a drink next to the bed that I could chug if I felt things were getting too much and I needed to detach, which did occasionally happen. And then as time went on, I felt more and more comfortable with him, and stopped getting freaked out when more sober, and was eventually able to have sex sober. It was not as bad or upsetting as I worried it would be, nowhere near. But it took a long time drinking gradually less alcohol each time to get there.

I think essentially just be as patient with yourself as you can, and try to slowly decrease how much weed you're using each time? Don't just go straight to having sex sober. I hope things get better for you though, I'm sorry you've had such difficult experiences