Been with 'd'p 9 years, I have 2 early-mid teens from a previous relationship, and we have a 5 year old together.
Pretty much since we've had the 5 year old, he's been unbearable. He will sulk if he thinks I'm in a bad mood (when I'm not I'm just sitting quietly of an evening after running the kids around and working all day). He's stingy with money towards me, he works full time, I work part time and we have a bit of universal credit too because our jobs aren't particularly high paying. He pays the rent, I pay for absolutely everything else and he will extremely rarely help me, but he always has plenty of money for beer, tobacco, lunch at work as he never takes anything from home, and random mcdonalds/toys ect when he takes our younger child out (the older 2 are usually off doing their own thing). Often he will disappear out all night, the other night I was up at 4am with one of my kids who had been sick and he walked in from a dog walk that he started at 8 that evening.
We have a HA house which we are both on the tenancy for, so that's my first issue with leaving. Neither of us are willing to leave, I couldn't even afford to private rent. The second issue is, he would cause so much damage for the kids because of how horrible he gets when he's hurt. Last time I tried to end things, a couple of days later he went barging into my older children's room at 9.30pm to tell them that I'd finished with him because 'they had a right to know'. He also loves to be the fun dad for the younger one, so I just know that he'd be taking them off all the time to do fun stuff and I'd barely get a chance to see them (obviously I would never want to stop them doing fun stuff together! But I don't think I'd even get a chance to do anything of my own with them).
I just don't know how I would even begin to do this but he's making me so unhappy. For context, in general he is a fantastic dad and step dad, and actually he is a good person but he's either not a very good partner or we just aren't right for eachother.