Your post belies a part of your problem ... You bottle things up, you have poor communication with your partner; plus this place is no use to you, you need a professional counsellor quite obviously.
For what it is worth, why are you still there?
Your partner seems to have little or indeed no respect for you and you apparently chase around after them trying to please. A fatal combination for any relationship.
Your partner is not trustworthy, that never changes, that is simply who she is. As middle age approaches, then perimenopause and mid life crisis start to raise their heads in many. That doesn't help create a peaceful life.
But in all honestly .... I have no idea why you are still there, I sure as hell wouldn't be. Do be aware that I am not bitter, twisted or screwed up in anyway .... I'm simply pragmatic. In essence your relationship has had parts lopped off with a machete and said parts will not ever grow back.