Well instead of using Prilox gel what you really need is a bit of dick training ...
everyone knows a friend who uses it but not themselves ....
if you practice a hand job 3 -4 times a week your problem should ideally get solved ...
I know and have slept with guys who do hand job and trust me guys who masturbate can fuck longer than guys who dont maturbate at all ..
and it is primitive thinking that masturbation makes u weak ...
you must masturbate with creams/ oil etc to massage your penis and thereafter also try Jelking search on google about Jelking ...
However for guys below 6 inches its better that they ejaculate faster as it relives women of tension to get rid of them ...
Yes, even I know a friend who uses it. But it is always better to consult a doctor and try other methods as Manohar has said.