No matter what I do or he does we end up invalidating each other and kind if bury our feelings deep inside just to avoid he conflict which is not good as the issues remain unresolved
I agree with you--the constant invalidating going both ways doesn't work.
I also agree that trying to bury the feelings and avoid conflict doesn't work either.
But having been there myself, I don't believe the constant invalidation is inevitable.
I was able to recognize the invalidating things I was saying, and just not say them, sometimes by simply saying nothing, if I couldn't think of a good and validating response. It wasn't easy, it took practice... .and sometimes I still slip up, but I do it maybe 1% as often as I once did.
When it comes to him invalidating you--you cannot stop that, and he probably won't unless he recovers significantly. I did learn two techniques I could use that did help me and help my relationship.
First, I learned to not take it personally--realize that my partner was saying these things because she was hurting and lost in some emotions, etc... .I would listen for the hurt she was feeling underneath the horrible things she was saying to me. It didn't work all the time... .and even when I was able to do this, I could be worn down.
Second, I learned to just leave that conversation, let my partner continue to stew, blame me, think invalidating thoughts, even tell them to the empty room, or somebody else if she wanted to... .but not participate in it, and thus not get hurt by it anymore.
I hope this helps you... .whatever choice you make.