Hi,doctor Im Really Upset To Tell U Tht Im 19

Hi,doctor im really upset to tell u tht im 19 yrs old and my sperm is releasing in 5 sec while im intercouse with my partner.im sorry to ask u wrong but i masterbate since my adult but since 1 yr i promis my self tht i wl not mastrbating.so now my penis is soo weak .plzzzzzz im req u tht gimme advise tht wat i hav to do for my penis strong and long time sex.