Letta, DB Lady has given you some good advice.
Now, I am not clear on how your ex-boyfriend can break up with you on the same day your boyfriend leaves you. Were you seeing both men at the same time? If so, please avoid that kind of mistake in future. It's not good form.
I am also confused on your being engaged and in love, but with a controlling boyfriend. Which one is the controlling boyfriend? Is he the one to whom you were engaged? And is he one of the above mentioned men who left you or broke up with you?
Letta, you need to get it together.
First, get your medical problems addressed. Next, seek out a counselor who will work on a sliding scale. If you are low income, you may perhaps even qualify for free services. You will never know if you don't try.
Life can seem hard sometimes; we have all been there. You have not "done" anything to "deserve" this, it's just what's happened. Your job now is to go on from here.
Take it one day at a time and do your best to focus on the primary goals, as DB Lady says. Right now, those are you and your children.
Forget about the boyfriend, the ex-boyfriend, the ex-husband and the fiance.
Good luck and take care,
jkgrandma