What Treatment Should I Take To Increase The Penis Size ?

hi,,, i am a male of age 25 , i used to have sex since i was 20years old.. starting i used to have sex for once or twice a week, when ever i used to meet my girl i used to have sex for at least for 3 to 4 times in 6 hours. later from 2 years i just was meeting my girl for once a week and used to have sex just for 1 or 2 times . from last 6 months my penis size has gone small. i didn t even used to do hand work much.. very rarely i used to musbusat.. please suggest me what should i do... should i go for treatment of allopathy , homeopathy or aurwadic...