My ex of 3.5 years dumped me last december three days before my cousin's wedding and about a week and a half before Christmas. I was mostly blindsided by it as well. It sucked really, really bad, and I think I know how you feel.
People can tell you that you're young, and while that's all with good intention for sure, it still probably doesn't make you feel any better, I'm guessing. My advice to you, hun, is to feel what you're feeling. Don't surpress it, and for the love of god, don't be a hero about it. When he smiled at you, I'm willing to guess that he did it out of a sort of self-benefit. By smiling at you, he probably makes himself feel better. (I got the "I'll be sad if we don't stay friends" thing. That's was him trying to make himself feel better right there). Don't force yourself to smile back at him unless you feel it is appropriate. This doesn't mean you should flip him off. He's not a part of your life now, really, so you don't owe him anything. You need to take care of yourself, and I think it might be a good thing if you find a new biology seat. If you're more comfortable sitting elsewhere or if it helps you cope or move on by sitting elsewhere, don't hesitate, do it. If you need to talk to the teacher, then you can explain what happened, but really, you don't owe anyone in your classroom an explanation.
You're friends are probably going to be the biggest support right now, and I suggest you get in contact with them and start planning stuff. Try not to focus on it while you're with them, otherwise you might miss how truly great friends can be, but if you need to cry, don't be embarrassed. You have the right to.
Feel what you feel right now, come to grips with it, and then move on and open yourself to dating only when you're ready. Your main goal is to just make sure that you are okay mentally right now. I hope things get better faster than expected, but I know they'll get better soon.
Everyone is different, and this is what worked for me. I don't think it applies here directly (at least I hope not), but I'll say it anyways. I'm 24, and when I was dumped, I refused to drink any alcohol or anything of that sort. I didn't want to numb the pain, I wanted to feel it and get over it. I think by refusing something ultimately detrimental, it helped me a lot and helped me move on faster. So eat your ice cream, go to .31 cent scoop day at B & R, but don't drown in it
I'm sending virtual hugs your way, Mew. A broken heart is a very hard place to be. You're strong enough to get through this.
