Hard, painless lump on the left side of my upper neck?

as for the lump they are quite common, I found one and read up about it and they are harmless bits of bone often found around that area, I think you must be stressing about that and the medication you are taking has had a bad effect compounding how you feel, I would stop the acne medication and try some evening primrose oil capsules - they will help with the stress , your eyes and your skin and they are perfectly safe, if the symptoms persist then get your urine checked for diabetes