Poly Confusion?

I'm trying to figure out whether I'm poly or not. I am a very caring person and loving to so many people, but at the same time I don't feel like I receive all the love back.

I've been doing some research and came across that rather than relying on one person for all your needs, it gets spread evenly across so as to not be a burden. My problem is, that whilst I don't want to be a burden and place all my needs on one person, I feel like I would be really upset if one of my partners were searching elsewhere.

Basically the scenario is that I am kinda seeing someone who isn't 100% meeting my needs (was in the beginning but isn't now) however I don't want him to be seeing other girls because i feel like im over available for him and his needs and like I'm always there for him when he needs it, and that clearly it's not enough if he were to look elsewhere, but then in reverse I know he's enough, there's just some stuff where he isn't meeting my needs and in a poly relationship, I'd be able to go and share those needs with others as to not be a burden.

I'm aware this makes me sound pathetic and weak and jealous, but I'm just trying to figure what it is that I need and require.