Hello, I am Human, and welcome to Psych Central! It's hard to know why we are attracted to other people. I'm sure you realize intellectually that this guy is not dependable and feels free to cheat on you. As you say, you are lonely, so I suspect that has a lot to do with it.

You have really worked hard to get your life together, and I think you should feel proud of yourself for that. It is unfortunate that you lost your job.

Is there anyone in real life that you can talk to about him and your losses? Perhaps some sort of grief counselor or other counselor? Sometimes clinics offer relatively cheap sessions for people based on their income (or lack of). I think that might help you to work through some things and get a new start.

Meanwhile, I hope other people here will have some ideas for you.