Hmm, I think I smell a breeder..
Honestly, I seriously doubt you will find too many people in the same situation as you. Not saying it's impossible, but there are very few girls who have 3 kids before they hit 20. You did not say anywhere in your post that you utilized any form of contraception. If you slept with 3 different guys and didn't protect yourself at all, then I simply can't pity you. You brought 3 shrieklings upon yourself. Taking care of yourself at 19 is hard enough, but to also care for 3 children? How are you paying for them? Do you work and leave the kids with a sitter or a relative? Dear lord.
Sorry for being so insensitive, but I cannot sympathize for your plight if you took no precautions. If/when you get involved with a new partner, please please please do something to protect yourself. You will only bring more suffering upon yourself and your children by giving life to yet another potentially unwanted baby. Don't let your children grow up in a miserable atmosphere, if they aren't already.