I think you should pack his stuff up for him, leave them at the front door, tell him it's over & you want him to leave, you've been unhappy lonely for a long time now & am not prepared to carry this on any further.
Don't worry about where he lives next, that's his problem not yours. He can go back to his parents, friends, uncles, grandparents, b&b.
He failed you, he's not been your partner in any shape or form, so don't continue to be one for him.
Once he's gone you'll be upset & hurt (nowt new) but you'll feel a huge weight being lifted from your shoulders.
I remember feeling like I was the mother 3 kids not 2. ... he's a grown man, he decides when to come home, when not, when to put everything and everyone before you so he can jolly well find himself somewhere to go.
I knew my ex wouldn't leave & make life awful for me, so I packed his stuff up and took it to his mums.
Then rang him, said I'm done, he's moved out & I gave nothing more to say, I'd tried for too long to make the marriage work but I was the only one & now it's over & I'll be filing for divorce.
I got the occasional nasty text message but I mostly ignored them. ... he wanted to talk & I had nothing more to say, so I didn't.
He sees the kids once a month if can be arsed, my oldest don't want to know him & my youngest ain't to fussed either.
He's not changed in the last 10 years, probably worse now.
I on the other hand am in a great relationship now with a lovely caring man, who is not a drinker (the occasional beer after a hard week), is a great step dad and I'm so happy.
Don't be scared of being alone, you have to close one door for another to open. I promise you, your doing the right thing!!