I'm in the same boat. Conversations about it go very badly - I also get the 'I'm just lazy' and 'I'm just tired' - he says there is no reason or secret about it. That said, if yours won't even admit that there's a problem, then that's even harder. I guess you just have to make it clear to him that you're unhappy and that you'd like to work together toward a solution. It IS a bit of a personal affront - nobody likes to be told they're not pleasing their partner, but he needs to try to understand where you're coming from.
Personally, I've reached a point where I feel like this is just him, and unless he wants to change, I can't make him want to have sex. Basically I need to decide whether I'm happy to give up regular sex for the many other positives in my relationship, or whether I need to leave. He's aware that I'm considering this, but I still really don't know what to do.
The only thing about your post that I found odd is the stuff about his dad. Is that a genuine issue? Or do you think it might be more of a handy excuse? Either way, him suggesting it's your 'fault' for not getting on with his dad raises a red flag for me.
Basically, I'm sorry, I don't know how to help. I do feel so much sympathy though - when you go past the point of 'affection without pressure for sex' and 'doing stuff as a couple' along with 'crying and shouting' it's very hard to know what to do. I've considered starting a thread here about this before, as I think there are a few people out there in this position and maybe we could all try to find a solution together - but currently, I've got nothing!
Homepride that sounds grim, but yeah going to pee multiple times during sex sounds medically odd, unless it was a serious kitchen marathon.