Masterbation

Okay basically how I masterbate is I sit down and get some lotion on three of my fingers. Then I rub my clit in circles really fast. It always feels really good and my legs get all twitchy and the inside of my vagina feels all warm and there's an amazing feeling but then it's gone in like five seconds :( idk if that's an orgasm or plateau or whatever it's called but how can I make it better or last longer??? And is lotion safe as lube or am I gonna get an infection????