Ugh. That stinks, LW, and it’s ok if your feelings are hurt. Mine would be, too!
I was listening to a podcast this morning. The episode was a compilation of listener grudges. One of the hosts pointed out that he thinks that at younger ages, people may not really understand the impact of showing up. I had that thought reading this. Your friends may actually be clueless. Or, since it sounds like you’ve already expressed your hurt feelings, you might be friends with mean girls. If you’ve already tried talking to them, I’m not sure there’s much else you can do. You can, however, choose where your energy goes and how much of it you give to these friends. Heck, I’m in my mid-30s and still sometimes find myself reevaluating friendships if they start to feel lopsided. When someone lets me down or doesn’t reciprocate my effort, I’ll stop making the effort and will invest more of my time in other friends and making new ones.
You can still celebrate your birthday without these friends! I know it’s not what you had in mind, but fun ideas include going out for dinner or doing a game night with your family, splurging on something like a trip to the nail salon, buying yourself concert tickets, etc. I can’t recall what I did on my 18th, but I suspect I celebrated in a small way with my nuclear family.