I have a lump on my chin, it is both under and on top of my skin, it's itchy when I touch it but at the same time it hurts, any ideas what it may be?

Hard to know. Without more description or a picture, it is hard to know. Would see a primary care physician and see about dermatology referral if he doesn't know. Could be an abscess or something like a dermal inclusion cyst, but I am just speculating. Pictures really help with derm issues.