What Causes Penis To Become Soft, Weak And Swollen?

hi ,my name is thomas ,i am 29 years old,i had problem with urination before and also while masturburating there used to be blood in the sperm .i consulted it with a doctor and he did prescribe me some medicine and after taking it for three weeks i found it getting normal .after a few week later i found there is weakness in my penis ,its getting softer ,swollen and weaker.i feel there is something wrong i feel with it.i went back to the doctor ,he said there is no problem and he prescribe me confide a ayurvedic medicine.i am mentally disturbed with it .what is gone wrong with it,is there is any cure for it