Feeling alone

So lately I've had a lot going on at home. I decided that this summer I wanted to focus more on myself and getting to know myself better. So that means I haven't been hanging out with my friends a lot and I recently got my wisdom teeth out so I missed the last party of the summer. But then I found out that my friends are the king one last party of the summer and I wasn't even invited. So I tried to see if maybe they just forgot to text me so I complained to my best friend that I was sad about missing the last party and you wanna know what she said? She said "oh well there's probably gonna be others". She completely lied to me. I just feel so left out and neglected by my friends. This is my senior year and I already feel like shit. I have known these people since Intermediate School and I thought they were my best friends. But recently they have stopped really inviting me to things and pretty much have stopped talking to me all unless I text them first. What should I do?