Horny and masturbating

This past week I've been really horny and I'm not sure why. Yesterday I masturbated 3 times, which is a lot for me. I like the feeling and enjoy clit stimulation. I've been masturbating for a while and think I'm cumming but want to make it more intense as it doesn't last very long. How can I have a full/multiple orgasm, every time I cum a little bit I become so sensitive and can't carry on. Plus tips on how to squirt?