Dear Só leigheas,
Sometimes life just beats the **** out of us and I know from reading your posts that you have endured more than most. Unless you are caring for a child (under 18), you have to take care of yourself first. You will eventually will be ineffective at helping others if you don't help yourself first.
If when you say you want to stop fighting, you mean SI, that can cause more problems than it solves. Can you confide in your fiance what you are feeling? If not, maybe you need to pull back a little from the relationship and work on yourself until you are feeling a little better. I don't know.
We can't make our sadness and rage stop. We can only feel it, accept it and evaluate it (maybe it's telling us something that we need to do in our life like set boundaries or change our own thinking). I think that sometimes the feeling get so intense that we'll do anything to turn them off (SI, legal and illegal drugs, sex, etc.). It's fine if we must do some of these things for a while to escape. We have to not beat ourselves up. To eventually accept our lives, our feelings. I am slowly recovering from depression and am trying to learn to accept myself and not feel embarrassed about all the mistakes I have made in my life.
I hope your misery turns a corner.
Sincerely, Myst