Hello,
Masturbation can never cause such problems. The most common psychological problems can generally be related to: inhibited sexual desire, anxiety disorders, depression, mental fatigue, stress, guilt, relationship problems, and lack of interest in sex by partner etc.
Give your diet an overhaul if you're lacking vital nutrients for growth and switch to foods for healthy hair and for fat hands, eat diet rich in proteins.
It is very difficult to precisely confirm a diagnosis without examination and investigations and the answer is based on the medical information provided. For exact diagnosis, you are requested to consult your doctor. I sincerely hope that helps. Take care and please do keep me posted on how you are doing.
Maybe this will help: conditioner should help thin and smooth down the hair a bit. (Actually, it's common to use hair conditioner on pubes because it makes them thinner and easier to shave).