Welcome to this forum. Man it's been years since i don't visit here.

Well, if may i advise you. First of all, if you can, seek profesional help: a capable therapist who can help you with your self esteem and your issues with your motivation. In here, not everyone is a profesional (It would surprise me to find one, maybe that's why i left).

I understand things get rough, and these times aren't quite helpful. Depression sure is a serious thing.
On a second note. If may i guess, your closest daughter just finished high school, didn't she?
This is a common one, the rebelious ideas and excitement of a new boyfriend. Since you and your husband (I assume) already splitted, you all are no longer a familly as a whole, so your daughters may be seeking other ways to fill that lack of attention, and without strong paternal figures, they can easilly get distracted by whoever catches their sight. It's a tough situation i recognize, but don't expect too much from your daughters.
Also, don't take this the wrong way, but you're the mother. It's not healthy to your kids to look at you this way. I'm not saying that you're a bad person because you're depressed, but you got a really strong hold on your daughter, and she ended up overwhelmed by the situation, and ended up going to an easier, more exciting path.
I can't really advice much on your kids or (suppose) ex husband.
As for familly, you sure you can't just let yourself in or something?
Either your mom or uncle..?
You're struggling and can't make meets end. If i would have to guess, your familly is you possibly best option: Making friends who could help is actually not that easy, and i wouldn't advice on seeking another partner unless you're already set both financially and mentally.
Hope this helps, and i repeat. Try to reconnect with mom and uncle, is my personal advice and what i would guess the best option. Remember i'm no professional.
Best of lucks and regards.