It’s hard to know exactly what’s going on from just reading this. But I can see that you’re becoming resentful of being constantly the listener/supporter and you sound like you feel like your needs are being ignored with the people you hang out with.
It’s possible that because you’re by nature a quieter person that they might’ve wrongly assumed you’ve got nothing to say? That can happen especially with less emotionally aware people. So they could just be the wrong fit for you.
I find big groups not the best fit for me either, it’s okay if there’s a purpose ie sports activities, but in conversation I’d feel lost. Have you thought about what sorts of activities and groups might work for you? Divine makes some good suggestions.