sir ,,one month before i was suffering from fever...after that Get your Health question answered in 3 easy steps Hi, I am Dr. David Bienenfeld (Psychiatrist). I will be looking into your question and guiding you through the process. Please write your question below. Ask a Doctor Now 139 Doctors are Online Public Forum Home » Men s Health » Men Sexual Problems Shrinking penis after masturbation. Weakness during sex. Treatment? i am doing masturbation from long time every day. recently i stop the masturbation. Now i doing masturbation after 20 days or month. so i observe that my penis size is decreasing. i doing sex with my girlfriend, that time i realize my sex stamina also decreasing. if it is problem please me suggestion on it. and i want to increase my penis size and sex stamina. ( my age is 23 ) please give medicine, oil or tablete etc. i want to solve my sexually problem.