I have an extremely painful lump on my thumb i can't sleep well with it. please help diagnose . it's size if pea red sore itchy?

Sore thumb: it sounds like an infection---but would need more information or a picture --to give you a better answer might be easier to go to Urgent Care or your private doctor

Lump: This could be a cyst or a boil like infection. Try warm soaks but if redness or a pus type discharge develop, an evaluation by a physician is indicated for diagnosis and treatment.

Hard to say: without seeing. but thoughts include cellulitis or whitlow. Need evaluation by your PCP