Sir, I Think I Have Recurring Ringworms Three Times.. I

Sir, I think I have recurring ringworms three times.. I took medicines but after compeleting 15-20 days of medicines it comes again. Ringworms are on my back, one was on my penis and others are on near by area of penis... What to do??? How to treat them??? Please advice as it is embarrassing me like anything and not allowing me to focus even on my work... Please help me..