i was thinking about this sentence:
I just feel alone because I'm starting to feel like, "You don't know how alone I feel over here, and it's not fair that I am the only one feeling this way!"
you probably wouldn't want them to feel alone as well but i can understand the feeling, "why should they be able to see each other a lot and i am alone". if b was hanging out a lot with a close friend and not another partner, would that be different? would it change anything in your needs or how you would ask to have those needs met? i find for myself that it can be helpful sometimes to look at it that way.