I have a boil the size of a dime on my inner thigh but it hurts very badly. should i go to the er?

Try a hot pack: You could go to an er, but an urgent care clinic would be much cheaper and likely give equal treatment. You can try hot packs, warm towels, or heating pad to try an increase blood flow to the area and help your body heal it. Sometimes boils heal faster if they are lanced open so they drain faster.

Prob not: Place warm compress on it several times a day...Eventually it will resolve or pop on its own.