Is it normal to masturbate 20 times/week or 3/day?

Most of the time, I think about my cousin who is 7 years older than I. She is 23. Once, she sucked my dick and finished before my semen got out. So, it wasn't good for me that time. My dick becomes hard and tall whenever I see her image. She fucks (almost weekly) 2 other guys, but, avoids me and often laughs at me. I am not ugly either.