Okay this may get a little long and be a little all over the place.

Been with my SO for 10 years as of January 5th the day before I got a message with a screenshot from some lady on Facebook saying he was trying to get nude photos from her. Our son turned 9 10 days later we also have a daughter who will be 2 in a few months but life has become way too chaotic the last few years. I am the main one working to pay the bills which I told him was fine because we really can't afford childcare along with everything else at least not until our daughter is old enough I feel to go to daycare or I can find another option. For years off and on since we first started dating he has had this need to talk to other woman online or over the phone or by text message he has become increasingly disrespectful to me and our son sees this and is becoming Hard to Handle watching his dad act this way I feel he's acting the same way. We argue all the time over dumb stuff like I work all the time and I'm currently not on my hormone replacement after having my thyroid removed and so that messes with everything I'm more tired less interested in sex and he'll hold that against me like I'm not going to clean the house today because you haven't given me any sex all week so he'll go a day or so and not wash dishes or not pick up the kids toys just stuff like that I'm to the point where I feel like i need to be done this is been going on for quite some time probably four to five years off and on and if he doesn't want to put in 100% on his part why should I keep putting in a 100% and staying where I'm not happy? The whole relationship has just become toxic I feel. There are times when we're fine and can laugh and joke which makes sense when you have been with someone as long as we've been together but mostly I'm just depressed and not happy and it's reflecting on my children especially my son who like I said has become angry and uncooperative at home and at school. I need to know how do I leave because I fear he will do like he did the last time I tried to get him to leave he will say he will leave but then when I tell him I'm serious I'm ready for him to go his own way he says he's not going anywhere or he'll break a bunch of stuff and leave for a little while and then come back and try to make things right can anyone out there help me as soon as I get my taxes back I'm planning on moving into a bigger place now that my daughter is old enough to have her own room should I let him come with me or should I help him get his own car and call it quits? Because I've already told him that this is the last chance if things don't change there will be no year 11 for us