I'm not sure how long you've been seeing your t for, so I'm not sure if this will help or not. But I know that it was only after I'd been seeing my t for like 2 years and he pointed out to me that he'd remained committed to me all this time and was consistent the whole time and cared that whole time and was pleased to see me every time and whatnot, that I was finally able to think about trusting him. He needed to make the implicit explicit because the implicit message was totally foreign to me and I needed it pointed out.

I also tend to only feel like the most recent time I saw him is the sum of all our experiences, when it's not. I really needed to be shown that I should be taking the sum of all our visits into consideration.

These weren't the sole builders of trust, but they did help me a lot. I hope there's something there you can use.