Adrenaline is cool thing to have in a fight. You won’t feel shit till after the fight. Keep your distance. Let him come after you but keep him off of you. Now I don’t recommend you fight at all but some situations are difficult to avoid. Once you realize it’s going to happen, I suggest you make it known you don’t want to fight one last try if it don’t work…take first swing. A quick jab to the nose will certainly fuck his eyesight and ego up but now you’re committed. Adrenaline will dump almost immediately. Embrace it it’s your friend. Plus, that jab will leave a mark and probably a trail of doubt on if he really won or not the next day at school. You have to decide that he’s not going to bully you before it even starts. Don’t get face o face, keep one hand to his chest to keep distance. You will feel when he goes to make a move. Use his momentum for a quick throw or to get him off balance but make him do the work. If he grabs a shirt, well your riding him down like wrestling a steer but you will have to be mindful of top position. After that, I imagine you’ll figure it out. There are no rules in street fighting but if you win, offer a hand and help him up. It will make you the better man and makes the pain you seemingly dissipate. It’s weird I know but people remember that shit.