I need help controling my mood swings?

is there something out there that will help me control mood swings, i dont have health insurance, but if you know of a medication a general doctor can prescribe that would help. or something other than just excercise that would help. i have really bad mood swings, one minute i'll think somethings great, the next minute i'll hate it. my mood swings are making me very indecisive and is cuasing trouble in my life. although i dont think i have manic episodes, could this be because of bi polar disorder. i have been diagnosed with depression before.