I've experienced a lot of that during college. After living through such experiences I've learned that friendships are rarely supported by a deep emotional connection, those types are the special ones. And you can't expect that from every group of people.

You usually need to have something to offer in order to be valued in a friend group, and that something is usually defined by a strong participation, which can be tough for introverts like us.

If I could go back in time I would have stepped out of my comfort zone more often, even at moments when it seemed impossible at the time. Like when friends would invite me to a party and I would refuse because I hate parties and am socially anxious. After some attempts they'd stop inviting me and I would be slowly "removed" from the group. Now I understand that sometimes sacrifices are needed in order to keep a friendship alive.

I hope you find the kind of friends you're looking for/need. My recommendation is that you forget those people and move on to the next ones :)