I've learned in life that anytime you start a relationship with someone that you have to "prove" things to, you are nearly always going to have an uneven power structure where they will continuously demand that you need to prove everything to them, while they can behave badly, disrespect you, do whatever they want, and generally keep stringing you along.
If you need to prove his trust in you, you never will. He has to trust you because he chooses to. Full stop. You can't make him. And he can keep raising the bar, day after month after year and keep making up reasons why he doesn't trust you. Which is how you get to a situation like the one you're in, where you've been trying to build his trust for years.
If he can't trust you because of "past experiences", he should not be dating. He should be having therapy until learns to trust again, and have healthy boundaries and make healthy requests of his lovers.
I think you should walk away from this guy. Put your energy towards someone who is going to be there for YOU. Unless something about having this long-distance and dramatic feels good to you in someway too. If you're shy and have a hard time with people, is it possible that you're staying in this because it's still somehow easier than dealing with people in person? If that might even remotely be the case, it could also be helpful to do to try out some therapy and work on yourself.
