Your problem

Take your car down to an auto parts store to get it tested....I work at Discount Auto in Palm Harbor, florida as a parts pro....I can tell you right now it sounds like an alternator problem...It has to be kickin out a certain amount of amps in order to keep your battery alive and your starter kickin.....But the only way you'll know for sure is to get an ARBST tester on it and see how much amps it's pullin out.

Manny