As long as you don't let it take over your life, it's okay. But your title says it is "all you think about sometimes." Sex is nice, but it ain't all life is about. Do you have any hobbies? A job that keeps you busy? Are you looking for a special person to share your life with? I gather that you are getting concerned, so you are seeing it can get out of hand. (Ha--pardon the pun.) Avoid pornography and anything that keeps this topic in your mind all the time. It's difficult enough to avoid hearing/seeing about it this day and age, when about all TV shows and movies emphasize is this topic.

Also, what's this need to feel humiliated and degraded in order to have an orgasm about? That doesn't sound healthy to me, anyway.

I agree that masturbation is normal, especially outside of a love relationship, so you shouldn't feel embarrassed about that. But I do believe you could have a healthier sex life than evidently what you are experiencing..... Contrary to what the other folks say, I frankly think it would be helpful for you to talk to a counselor, to hear what he/she says. They are the "sexperts."