Re: High libido, not enough sex
I don't know if your level of interest in sex is too unusual. You are still young and your hormones are still very high. It is possible you could be addicted to masturbating. There's a physical limitation that it seems like you should probably have reached. If you're chafing your penis, you can't keep that up. Soreness after sex/masturbation indicates some damage that can accumulate to seriously desensitize your penis (or worse) if you keep at it. To relentlessly pursue sex/masturbation despite the fact that it's damaging your penis definitely indicates a problem (IMO).
If your interest really may be excessive, you might have your gonadal hormone levels tested. Very high levels might possibly indicate bad things. Have you been examined for testicular cancer in the past 3-6 years? You might find dietary changes can lower/normalize your libido.
Personally, I think you should at least approach sex with your partner differently. Find out exactly what it is that she might want you to do differently that would make her want to have sex with you. Maybe you need to behave just slightly differently in how you indicate your interest in sex. Her declining might indicate that she doesn't enjoy sex as much as you do. You might need to make more of an effort to make her enjoy sex with you.
If she ever experiences pain or discomfort in sex, you're not doing it right. She should not. Or it's possible that your differing hormone levels are irreconcilable and you shouldn't be together.
Maybe you just need to work on other aspects of your relationship. Are you taking care of each other otherwise? It's important to talk to your partner. You need to know what she wants.