Oh I hope you told him you haven't had time to become more interesting because you have been carrying his dead weight around for years.
And that there has been no inspiration to exercise because his negativity drags you down.
It's easy to turn around almost any argument to the other person like he does.
A strong, supportive husband and father who engages with his children, does household chores and jobs, values the mum of his kids, loves and laughs freely. Doesn't sound like he is any of these things.
Sounds like he has been a misery to live with for years.
"He would like to continue living together" yeah I bet he would, he doesn't have to do fuck all, even teach, play, talk to his kids. If he doesn't have you he is going to have to empty his own bins, cook and clean, wash and out away his clothes. Put a bit of effort in to get a shag.
Basically get defiant not sad.
He hasn't loved you for years but has happily had you running around after him I am sure.
So stop that now.
Separate his laundry, say fix yourself something to eat. When food shopping say I don't know what to buy you. Don't do any admin, book in car for MOT, just pick up a prescription, send a birthday card to his mum. Just stop now.
Say "wish you'd mentioned not loving me earlier I could have stopped all this sooner".