I have this boil like thing on my vaginal lip, it's painful and has a white thing on top, should i be worried, and what should i do?

See a doctor: any lesion on your vagina should be seen by a doctor to make sure that you do not have an STD that needs antibiotic treatment. It's possible that this is just a boil or bacterial abscess that can be treated with warm compresses, but see a doctor just to be sure.

Abscess: You are describing an abscess. You should see your PCP or OB/GYN ASAP. You might need to have it drained or placed on antibiotics.