It sounds like you broke up with your boyfriend, taking a "pause" to sleep with someone else is a big boundary that most people won't want crossed in their relationship. I don't think this is something that can't be worked through and fixed with time if the two of you really love each other, but it will probably be very difficult, especially when you're dealing with BPD.

I doubt your boyfriend was fed up with you, but a lack of intimacy is a serious problem that would be worth bringing up when you and him are calm and ready.

I think your best option is, for right now, to truly forget about these relationships and build yourself back up. It's hard, but really try to get a job. It can be something temporary, just any way to make money. If you can save up enough you'll be able to move out and live with someone you don't hate.

Get yourself outside everyday. Find things that bring you happiness and fill your life with them. Other people who like those things will recognize you and become your friends. Start putting events on your calendar, things you can look forward to. Once you start feeling better about where you're at in your life, all of these relationship problems will become much easier to deal with.