Is it normal to masturbate or be horny all the time?

Okai, lately for the past two months i've been really horny and and can't seem to get enough of sex.
I have sex with my boyfriend just about every two days. And if I don't have sex with him, I masturbate. This is a constant thing for me.
I'm eighteen as well...maybe its the hormones acting?
Please let me know if this is normal