Part of a deer tick remained in my skin when trying to remove it. will it come out on its own? or should i see a doctor?

Probably OK.: It's common for the head to remain after you remove it, and that's not a problem. But if there is any chance that it was a lyme disease-carrying tick, and it was attached for at least 24 hours, you are at risk for lyme disease. If you don't know how long it was attached, you should see your doctor for lyme titres (one now, one in a couple of weeks) to be sure.