Fuzzy,
I have to tell you that this kind of thinking baffles me!

You say that his masturbation triggers feelings in you of feeling not good enough. And yet--he came to you first! You yourself said that he comes to you, YOU REJECT HIM, and then he goes to his hand. So where do the feelings of you not being good enough come in?
I am not attacking your feelings, I am just honestly confused about them. I don't see where him taking this route is any reflection on you whatsoever. Believe me, he'd rather have you any day.

Are you saying that you feel bad about yourself because you feel that you can't keep up with him and that you are not "enough" to satisfy him?

And what about turning that around and trying to frame it in a more positive light? Something along the lines of: I turn him on so much that there's NO WAY I could keep up with him; so he does this (mb) out of love for me and in order to give me my space and peace.

Cause, really, the alternative is that he bothers YOU every time he wants sex and I'm sure you don't want that. You are most certainly not a piece of meat to him but you must understand that his body operates differently than yours. I'm willing to bet that you can go days without sex without feeling like you are going to explode, well, he can't. He starts getting fidgety and restless and to the point where his thoughts can't focus on much else. This is not him being an ass, it is his BODY! It is the way it works. Much like some people have fast metabolisms and some slow.

My H never masturbates and never has the desire to do so. I used to think that was a sign of him being less sexual than me and therefore, inferior. (cringe) But I have reframed that thinking into: I take such good care of him that he has no NEED to mbate.
Now the truth is that he wouldn't do it regardless, but that is what I say to myself and it is the truth also! In other words, there are more than one version of the truth. Tell yourself the most positive version and perhaps it will help you deal with this situation.

All the best,
Honey