Can you grieve for a family you’ve never had?
Yes you can, and I think that's exactly what you're doing.
I want to forget it all happened. I feel like my DH doesn't care about me or our relationship and he knew how much I wanted to have a happy family and I don't understand why he would do this.
Forgetting it happened doesn't change the end result, which is that you will never have the relationship with your in-laws that you desperately hoped for.
You want your husband to stick up for you against them and he doesn't because he still sees them 5 times a year. You're warring with yourself over your hatred for them, his disloyalty to you when it comes to them, and your love for him. You would love for him to stand up next to you and say "I'll stop seeing you unless you start treat WillChangeItBack better" but it doesn't change the past and it won't change the future, because you still don't trust them.
You're asking about the conversations because you still don't trust either what they're saying or what he's saying to them. You're trying to micromanage his relationship with them because, I think, you're worried that they're taking him away from you... when in reality you're pushing him away.
You say you want to forget what happened, but I don't think you do. I think you want to move on from it and you're not sure how to, or what you want (relationship with them wise that is). You know that a good relationship with them might not be possible, so what will you settle for? Cordial treatment? Or simply no interaction with them?
If you have children he will take them to visit his parents, and I think you know that, and I think that's another thing that you're grieving. Because you're trying to imagine your future but you can't, because you're stuck on what arseholes they are (and he was).
I don't think you should have married him with this anger still between you, and I think you realise that too.
I am angry all the time and feel like I am being punished for something she did wrong. I don't know what to do.
You said "I can’t remember her exact words but she told me not to come as it wasn’t a social event. My BF/DH then spoke to her privately and told her that she was being rude to me and that was not how to speak to people. He begged me to come with them but I couldn’t I was so upset and stayed in their house"
You later said "she started to email and call my BF/DH saying that she didn’t know what my problem was." and that "She calls one night in October 2013 and I tell DH/BF not to tell her what I’ve said (about her being inhospitable to me) as she will lose her rag. Well he did and she exploded."
In all honesty, though she was a bit of a bitch, your DH started the really aggressive stuff by telling them what you said. He also continued it by not telling her to quit it.
Your problem is not so much with them, as it is with him. He does not have your back when it comes to his parents treatment of you and he continues to show that. So you need to decide whether you're okay with:
- not having any relationship with them
- attempting to have a relationship with them, of some sort
- leaving your DH
You're not happy so you need to do something different. You can only control yourself and your reactions, so I would speak with a counselor to try and get to the real truth here... which is that your DH will never change so you need to... in whatever way that works out best for you.