We have been together for five years. He is very loving and caring, but there is a long history of him lying in our relationship. Sometimes he will flat-out lie to the point where he’s gaslighting, or sometimes he will hide and withhold information out of fear or aversion to conflict. He doesn’t do these with malicious intent rather I think it’s a learned coping behaviour for him. Some of his lies, I have accepted with understanding, but there are others that still bother me which I won’t disclose in detail but they often revolve around his ex, this attached girl he has had a sexual thing with throughout our relationship, and his attraction to me. We had a big moment last year where all the lies came to head, and we have both been trying to make meaningful changes — him being more consistent and willing to talk to me about the harder things in our relationship (i.e., not reacting with anger), and I have been trying to be reassuring on my end and regulate my emotions more when I am upset. This has gone well in some instances and very badly in others because of how upset I get when I can sense him withholding or deflecting. I want to give him the benefit of the doubt but I am still very guarded and feel he is not being transparent about his feelings towards our relationship, being monogamous, and his sexual attraction to me. I think he much prefers this other girl. Is there anything I can do to get him to be more comfortable about expressing any dissatisfaction in our relationship so we could try to work on it? What are some ways I can create a safe environment for him to be open about his mistakes, perceived or real? I would also really be grateful if I could get some advice on how to deal with relationship anxiety. I know that rebuilding trust takes two people and I know I haven’t exactly made it easy for him but I am working on recognising that there are things I just simply can’t control. Sometimes my anxiety gets to the point where I do things that are unhelpful like looking at the other girl’s social media for some sort of reassurance she’s out and not sending my guy pics but this makes things inevitably worse because I always manage to see signs that they are continuing their thing (like sharing the same kinds of posts and memes).
Tl;dr our relationship has previously broken down due to communication issues — what can I do to prevent this from happening again? And what are some ways I can encourage him to make positive changes?