plonisalmonis, that sounds very painful. I hope you feel better soon.
Regarding your diet, a GF diet is not likely to help unless you have dermatitis herpetiformis (DH), a form of celiac disease. But since DH is usually symmetrical (appearing in the same part of hands, arms, legs, etc), this seems less likely. If you do have DH, there are medications that can help in combination with a GF diet.