Wait until you get to be in your 40's and things really change.
Soooo true. I started having new PMS issues in my mid-30s (after I finally went off the pill). No biggie. Then I turned 40. It was like someone turned up the PMS volume to 11. It was so bad, I actually went in to get checked for ovarian cancer.
My gynecologist said, "Nope... this is just what happens as you age and your hormones change. It's gonna get worse before it gets better!"
Things that might help:
1) Try eating super healthy, low-carb, no-sugar meals in the week before and during your period.
2) PMS can be heightened by vitamin deficiencies... especially B-complex vitamins. Take a B-complex every day in the week before your period and it will help. (Advice from my gynecologist.)
3) For painful, swollen breasts, try taking evening primrose oil. My breast doc recommended it... I take 1000 mg with breakfast and never have breast pain. (If I forget to take it - bam - breast pain comes right back.)
4) Exercise, exercise, exercise. Sweat-producing exercising (e.g. aerobics, pilates, a quick walk or jog) will regulate your cycle and flush any excess hormones out of your system. (Excess estrogen is one of the biggest causes of PMS.)
5) Along the estrogen line, avoid any foods or plastic products with estrogenic effects. Buy only organic meats; never cook food in plastic; stay away from bottled water in plastic bottles, etc.
6) Remember to hydrate. The water will help to flush the estrogen and excess hormones out of your body. Along these lines, try to limit alcohol consumption just before & during your period. It pumps up your hormones and dehydrates your body.
That should help, but don't be surprised if you find yourself eventually dealing with other unexpected issues... breast lumps; weird abdominal pains; mid-cycle bloating, nausea and/or sore throats; acid reflux; heightened allergies; fatigue, etc. (I'm not listing these to make you dread hitting your 40s... just to head off the inevitable anxiety attack.)