I am not going to say I have all the answers here for you.
But I know how things can be very difficult with this stuff. I know the drinking bit like the back of my hand, and I can tell you that getting rid of that coping mechanism can make dealing with the rest easier.
I can't relate to the other stuff as I never had a significant other, and only recently has my job situation been anything close to what I have been capable of.
But you need to keep reaching out and get past this space you are in. I know the space, because I have spent a lot of time there. Only since I have started reaching out has it gotten better. It sucks that people are not being supportive like they should. But at times like these, you can't let the inabilities of others get in your way of making things better for yourself. You didn't ask for or deserve what happened. And you are right I think in that you can't do it alone. I know I tried to make it all go away without the help of anyone else, but it didn't work for me.
But if you can't get the support from where you think it should come, reach out here as much as you need. Continue to see a therapist, and if who you are seeing isn't helping enough, find another. I know this isn't easy to understand when you are in a bad space, but it can get better. I can't say I know how you feel or what you are exactly going through, because we are all unique, but I can tell you I know what going through really crappy times are like and I know how trapped one can feel by them. Hang in there and let me know if there is anything I can do, or just keep reaching out here with whatever it is you are feeling or going through.