My boyfriend opening up troubles

My boyfriend is open with certain situations but very closed off with how he feels etc or if something is wrong.  He has been fucked over in the past by relationships, cheated on etc. I'm not like them, I'd never cheat or wanna hurt him. I want him to open up to me I told him I'm not like the others and that he'll try opening up to me but it's something he finds hard to do. Im happy to wait and just get him to know I won't do anything intentionally to hurt him. I wanna make him believe me. Anyway he said he has told me stuff that even his own family don't know off which means so much but I'm just wondering any helpful tips with how to make him trust me more or to be able to open up to me???
Sorry if know of this makes sense so tired lol