Feeling this also. I was considering making something similar that's more math oriented because it makes a huge difference having someone to talk about these ideas with. Math in particular can get pretty lonely sometimes!
Also just wanted to comment to OP that the site is really cool, feels quite polished. It's impressive that you're just 18 and you created such a cool and seamless experience. If you add mathematical topics (or create some way for users to add topics), I'll be a lot more likely to use it! Another suggestion would be to create some way for me to invite others to use the site -- some shareable link like "Join <user>'s study group!" not necessarily with that verbiage
Also just wanted to comment to OP that the site is really cool, feels quite polished. It's impressive that you're just 18 and you created such a cool and seamless experience. If you add mathematical topics (or create some way for users to add topics), I'll be a lot more likely to use it! Another suggestion would be to create some way for me to invite others to use the site -- some shareable link like "Join <user>'s study group!" not necessarily with that verbiage