Many people I've known have had similar problems... and as a few have said- it turned out to be endometriosis. For some they also had major cysts. Whatever the case was, they all required medical attention.
I myself don't have insurance, and because of that, I'm on a payment plan. (I pay $50 up front, then at least $20 a month after that...I'm sure it differs from place to place, but that may at least give you an idea) Even if that's something you can't afford, you need to go! If there is something wrong that doesn't get taken care of soon enough, it may cost you a lot more in the long run (financially, emotionally and physically) Hopefully you can find something like what SotallyTober mentioned.
Oh, and about your breasts- Mine get super tender around my period, it turned out I have fibro-cystic breasts, not a major health issue at all, but since they're "lumpy" I need to be more aware of everything when I self-examine them. It's reccomended people w/that stay away from caffiene.
Good luck, and I hope you get help for it soon!!!