How to trust?

Okay, so I've had a lot of bad things happen to me in the past, long story short, the worst thing is where the police can arrest me if I send nudes and they are told. I have had severe depression, a lot of breakups/losing people close to me, suffering from self harm, social problems, and you should understand what I've gone through. I've never had much trust in people close to me because of those things which has affected my ability to form strong relationships with people. Me and my bf are really close, but I find myself being over protective about many things because I'm worried of the endless possibilities of me losing him. I didn't want to be in a relationship anymore until I met him, and I'm really glad I did, but I want to learn how to trust him more cause he deserves it because of everything I'VE put him through. You ladies have any suggestions that can help me?????