Hi, Anapit
I was very much in your situation 2 years ago,then split (10 yr relationship).Sole earner, good income, but long hours.
ExP had a p/t job initially for a few years (2/3?) and relationship worked ok. he then lost it, and became SAHP and studied p/t, again enthusiastic in the beginning, then rather less so.
Last 3 or 4 years did nothing- did not look for job, did not study,did not do house work. Did sort of look after DS (born 2006, but I mean "sort of" (DS in nursery 3 mornings/ week at that point). Complained when I said he should do housework, or find a job- housework was womans work, but did not want to work and put DS in Nursery more, either. Was annoyed I would always earn more, but happy to spend my money.
Verbally abusive, called me lazy (FFS, I earned ALL of the money and did MOST of the housework). Controlling, undermining.Severe MH issues (properly diagnosed, bipolar)
Very much had the "poor me" attitude, everyone was against him, and very entitled- because his failure was everyone else's fault, the world (will say: me) owed him a living.
Note he is an "ex"
I am 46. Work 60+ hrs/ week. I have 3 children- 2 teens, and 1 pre-schooler. All my family live abroad, and due to ExPs odd/disturbing/ controlling behaviour, few friends.
I cope. The first few months I lurched from one crisis to the next, but it now runs smoothly. I am tired a lot, but nothing like the bone-weary exhaustion I had before. Never regretted splitting.
( I lost my lovely mum to breast cancer 10 years ago. It was dreadful)
Sorry for long post 
Take care, and do what is best for you.
If your kids are teens, they will get to decide who they want to live with, anyway, legalities should not be involved over 12 yo I think.