OK I did a really stupid thing and talked to him. It went as you might expect. It's only just happened this afternoon so I'm posting here just because I have no one else to talk to.
I had a bad morning, a bit spaced out, a bit depressed, period pains, really tired, etc. I got up with the kids at 6, and went back to bed when he got up around 8. He took them out for the morning. I was still in bed when he got back around 12. He put on TV for the kids and came into our room, asking me what was wrong, saying he really wanted to know, wouldn't get angry etc etc. So I said I felt like our relationship wasn't great at the moment and I wasn't sure it would just be ok again once the current stress we're under goes away.
Of course, he got really angry - "nothing's ever good enough", "is this about that time I lost it with you?" "what are you going to do about it?" He shouted at me but didn't do anything bad, no names or kicking stuff or anything like that.
I can't really remember what happened tbh. I kept saying it wasn't anyone's fault and it wasn't his fault and it was just that our life had had more stress than most relationships could survive. I can't remember all the stuff he said, but he definitely got really angry again about the time I "threatened" to tell someone about the stuff he'd done because I did it to hurt him. I didn't. I said I wanted to tell someone because the secrecy was the thing that did the harm with my dad, and I just wanted to tell someone. Because it was a big thing that happened to me. I never threatened, I never wanted to hurt him.
Anyway, he was livid, said it was unfair to him because of everything else he's done to help me and support me with all the other stuff that's happened to me. Which is true, he has done a lot for me.
I don't really know what happened. I ended up locking myself in the bathroom again, but our new place you can unlock them from the outside so he just let himself in after a while. I can't remember what happened, I remember being terrified and I nearly fell over the laundry basket to get away from him - stupid, since I was cornered in the bathroom with nowhere to go, I just crouched under the sink, squeezed between the sink and the shower, I must have looked so pathetic tbh. He didn't do anything. He made me some tea at one point. He didn't kick any doors or whatever. I'm just terrified of him when he's angry. I honestly felt like he hated me this afternoon, the way he spoke to me.
He sat on the floor at the door once he'd come into the bathroom, and told me all this stuff I can't remember about how good our relationship was, did I not see it that way, it was really hurtful for him to think I didn't think we were meant for each other, and him being "abusive" was so unfair because of all the good things he's done over the years.
Then we were supposed to be at a friends for dinner so he gave me 10 minutes to decide if I was coming or not and get ready. I got ready, he asked if I was coming, I said I didn't care and what did he want me to do, he said he thought it would be good for me to get out so that's what we did. Dinner's over now. I'm staying elsewhere tonight (which was planned already and not a result of all this). I feel awful. He's said he loves me a few times this evening, all the usual nice stuff. He bought me flowers and chocolate and wine.
I feel just scared and empty now. And how can I tell anyone? He's made it really clear I'm "allowed to" as long as it's "fair" to him. I don't think he'd ever forgive me if I told anyone tbh, because I could never tell it in a way he felt was "fair". If I tell my SIL, I'll have to make her promise not to tell my brother, and then that's just a burden on her, and she has young kids of her own, plus it doesn't seem right to ask her to keep my secret from her own husband, esp. when he's my brother.
I will answer the questions from @Jane379 (thank you so much, Jane, you and a few other posters have been so kind to me). And of course I don't expect any replies to this. I know people have been so generous already with supporting me and I've been really frustrating to engage with. I just wanted to write it down because I'll read over all this some day to remember what happened and what it looks like from the outside. It's literally the only way I have to actually get all this to exist outside my own head and his version of it. I can't even remember all that was said, but I felt like - how is it I'm the villain, when I'm the one cowering in a corner, crying? And, also, if he actually loved me, would he not be sad to hear that I felt like our relationship wasn't great, and sad that I was so sad? And instead he was just angry because it was unfair to him.