I could have written your post OP, all bar regarding your parents. Sorry for your loss with your father passing, and now your mum not being well.
Also had to be the good wife, appearing that all was well for work do's and sorting out all the financial side. Argued constantly as claims not put in when they went out on yet another 'team building' night out, for which he paid from own bank account. It got so bad that we were heavily in overdraft, couldn't pay school fees so had to change the arrangement with the school (yearly to monthly). He also had an affair some years back and I thought that I was past that and had dealt with it.
One day, there was a petty argument ..he said he told me something important, which he didn't. He argued blind he had told me, and that I had a memory problem, couldn't remember anything he told me etc etc. I know I wasn't told as it was something that you would either know or wouldn't (regards to a overseas trip he was taking which he failed to tell me about until the night before). It was the final straw for me. Yes, I was the doormat, although it didn't see it until that moment, when I realized lots of things at the time as well.
When he got back from the trip, I asked him to move out. Things weren't rosy for a long time, but there I was trying to fix it all the time, make his life easier (and mine hell as a result). I was done, finished, over it. I just couldn't do it anymore.
I don't know what the answer is for you OP. Only you can decide that. I am not one of the LTB team, but you have to think of yourself for a change. I also have two teenagers, so I know the angst there as well.
I found posting here a good thing for me. I didn't just do it to get replies (which majority of were spot on and helpful). When I posted in the moment of turmoil happening around me, I could read it back again the next day or week, and realize the constant shit storms I was dealing with. By the following week I had brushed it off, and was dealing with the next issue. But the thing I had forgotten about from the week before, was glaring at me, and it was still unresolved. I just put it down to normal, but it wasn't and isn't.
One thing that I have noticed though, since separating. Those nights out with the boys and all the team building events are far and few between. Even trips for work have been reduced to the absolute minimum. I see now that he was going away for ridiculous reasons, and the nights out were so that he didn't have to come home. He denies this of course, but I see things a lot clearer these days.
I wish you all the best 2scoops. Keep posting, as you are not alone in your situation, I can promise you that. Even if you just need a sounding board, or you are looking for advice from others who are or have been in the same situation. Getting it out helps a lot.