I have a 13 year old daughter who is also an empath and we've had good luck sending her to school with protection crystals to help her survive and be focused. As you are experiencing she deals with a ton of drama and negative at school and through social media. Typically black tourmaline and black obsidian work best to help sponge up that negative before it gets to you. I gave her a blue lapis and black obsidian bracelet that I found on Amazon and it has really helped. As a guy you could just carry a couple small tourmaline stones in your pocket. But everyone is different and I find contact with skin helps (I also wear a protection bracelet under a long sleeve shirt at work).
The crystals do help but aren't going to be 100% effective. I think most days they keep 60-70% of negative off of you. But as others have noted, you need to be grounding every day after you get home from school. And on especially stressful weeks you may want to do a grounding exercise before and after school. Most people ground through meditation and when done right you can literally feel yourself becoming happier and lighter (like a weight of anxiety being lifted from you). If you do that daily then when you go to school the next day your armor is at full and you can handle a lot more than usual. If you want additional grounding tips then just private message me as I'm happy to share details. Best of luck to you.