I have to admit, I didn't read all of this.

Here's the deal - you should never feel guilty for masturbating. Period. Your partner does not have control over what you do with your own body. Period. And, typically masturbation is healthy in a relationship, because a perfect libido match-up is a rare thing.

It is categorically not cheating. Period.

But it seems (based on what I skimmed) that you're worried it's pulling from your time together in long distance phone sex / vid chats. That's another story. If you feel like you're masturbating to avoid sexual encounters with your partner (including virtual sex), that's a problem - it suggests something about the sex isn't working for you. You mentioned that you didn't like the "money shot" vids he was sending you, so to speak. That's not at all uncommon. I've never had good long distance virtual sex, but I think the key is really setting the mood - it's more about talking to each other, getting each other worked up, trying to share an erotic experience through your communication. I think men have a harder time understanding this because more men are aroused just by visual stimuli - i.e., you send him a naked photo or video and it's an immediate turn on. If that's not working for you - that doesn't mean there's anything wrong with you. That's really normal actually - lot's of people (especially women, but also men) just don't find videos/photos of genitals very arousing, they're more aroused by the experience.

Try to figure out what things your partner does that arouse you, and communicate those things to him. Just the process of telling him what turns you on will probably be arousing for you both, and might jumpstart a nice long distant session together. But most importantly - masturbating is not cheating. Never. You have that bodily autonomy, always, and you should not trust anyone who tells you you are not allowed to masturbate, period.