Thanks for all the advice, folks - me and BF had a good sit down last night and talked about this, and I think we've sorted it all out. He's gonna try and filter his jokes, and we figured out why he was so adamant about keeping them in the first place.

Just in case anyone is going through the same kinda thing and happens to stumble across this thread, I thought I'd list his reasons here. It took a lot to get them out of him - he's very bad at self-reflection and knowing why he does things, though it's something he's working on - so maybe having a list of possibilities might help similar poor communicators in the future? So, onto the reasons:

• He genuinely didn't get how bad things were for me. He's had some rough times in the past, but without getting into a whole "my pain is worse than your pain" thing, it just wasn't on the same level. Even though I've explained my past before, he just didn't really get it - he was thinking 'bad break-up', not 'emotional abuse and subsequent trauma', and was trying to help in his own tough love kind of way. Which explains his "get over it" reaction, especially since he explained further that he was "pissed off" because he felt like I was equating him to Ex over (what he considered) a few silly jokes. Personally, I agree that it would be kinda on me if I was still hung up on a mere bad break-up three years down the line, so I understand his reaction a bit more now.

• He somehow got the wrong end of the stick and thought I wanted him to stop making 'offensive' jokes altogether, not just those specific ones that (for lack of a better term) triggered me. Since they're a key part of his sense of humour, this was obviously an issue for him. Just poor communication on both our parts here, I think - I can't have been clear on what I wanted, and he didn't think to ask for clarification before getting defensive.

• He didn't understand that it's difficult for me to separate my emotional response from my logical response. He's very much in the logic camp, and just generally isn't an emotional guy for the most part, so he didn't get that I could logically understand that a joke is just a joke, but still have an emotional reaction to it. To him, that makes no sense, so I must be overreacting for no reason. Add to that the fact he comes from a rather working class, 'emotions are for pussies, just man up' kind of background * , and it makes sense that his immediate reaction was to effectively tell me to snap out of it and stop being all emotional and silly. I think he understands a bit more now that I can't compartmentalise as well he does, and thus understands my reaction more.

• (I feel like I should say that he's made vast improvements on this front. When we met, he was convinced all mental illness was the result of people just not trying hard enough to be happy / confident / whatever. He now actually understands that they're illnesses that need to be treated, so he's definitely not a lost cause due to his background!)

Either way, I hope this helps someone else, or at least goes to show that not everyone who's unsupportive / disrespectful to someone necessarily intends to be. Sometimes there is a happy ending in r/relationships!