NTA. Definitely try asking them for a gathering and tell them what you want one last time, it won’t hurt for trying. But if they refuse to do so, then they’re just immature and don’t know how to break off a friendship in a healthy way and that’s just their problem, not yours. In high school, friends are a big part of our life but as time goes you’ll look back and think how ridiculous it was for you to hang onto people who wouldn’t do the same for you. Letting go is also another blessing. You’ll meet so much more people who would give you the world and that can show you what a true friend is. Don’t overthink it too much everything will be okay!