Bicep injury

About 10 months ago I had an armwrestle with someone, and afterwards my bicep really hurt. I normally did pull ups every day, and sometimes weights, but it has hurt too much to do them. For the first few weeks after it happened, my bicep hurt, but now its ok. However, if I try to start doing pull ups again then it feels like its under too much strain. I tried doing bicep-curls with small weights to ease myself back into training, but after a while that started to hurt my bicep too. Does anyone have any idea how to sort this out so that I can start exercising properly again?