Hi, I Have A Problem. I Never Really Did Masterbate

Hi, I have a problem. I never really did masterbate much but when I did it would be 2 or 3 times a week. And I wood do it dry like using my skin not any lubercants because it felt better but after awhile I noticed a sore where my hand was and I would put aquaphor healing Cream on it and it would help a little then it would get try and flake off and then I'd but lotion on it and i wouldn't masterbate for a week but then when I thought it was healed I would masterbate and it would become sore again.? Any suggestions? I know it isn't any diseases cause I never had sex or anything . I have a gf now and I just don't want her seeing it and thinking I have something.