[throwAwayFr]

Maybe its because I see people doing the same or less work as me, are getting paid (and therefore appreciated) more.

I don't know what a promotion or recognition would look like, or how i might ask for one?

[onion2k]

are getting paid (and therefore appreciated) more

I'd be willing to bet many of them feel exactly the same way you feel. They'll feel they're under-appreciated and unrecognised for what they do, and they'll think more money will change that. It won't. How much you're paid is not a sign of how well you're appreciated.

[throwAwayFr]

I get what you mean. But I honestly think I'd feel at least a bit better if i was financially doing better.