I punched my classmate because he was making fun of me, but only I got in trouble, am I in the wrong

I'm a 17 year old male, living in the UK and currently in yr 13 or Sixth Form. For my 5 yrs of secondary school, I was physically and verbally bullied. Not by 1, but by a ton of people and for many different reasons. In the UK, you would've called people like me a 'neek'. And after 5 yrs I thought that once i get into sixth form, people will finally show me some respect, but I was wrong, the verbal bullying continued into yr 12 and people were still making fun of me and i was still the butt of everyones joke.

Because of this, I thought to myself, why does everyone feel the need to pick on me in particular. It hit me. All of those years is because i was an easy target. Every single time someone did something to me, i would just take it and not do anything about it.

But you may be wondering, why don't I tell the teacher about it? Now in my pov, telling the teacher is only a short term solution, because what do teachers do, they either tell you to ignore them, create a barrier between the victim and perpetrator, or they try to make the bully understand why bullying is wrong, and of course, the best solution is the last one, but what's stopping the next person from taking his place and bullying me again, that's why instead of changing the bully, i chose to change the way I react to it. And for verbal bullying, i chose to use my words, and if they don't take you seriously, demonstrate with your fists.

That's what happened the other day with my classmate. He's someone that usually made fun of me, just like everyone else, and on that particular day, i was thinking, if i don't do anything now, it will never stop, so do something about it, maybe then, you'll set him as an example and people will leave you alone. So i got up and went over to him. I started by using my words and said "If you want to fight, then come outside". As violent as it sounds, I was just hoping he would take that as a message and realise how bad it has gotten, would finally realise i'm fed up and would stop making fun of me, but instead he never took me seriously and laughed at me. Not that everyone took me seriously anyway. So I ended up sparking him in the face.

So far I was the only one in trouble. I was isolated for 2 days, had 2 talking to's about my future and the other dickhead was let off scot free, with no punishment for bullying me. Not only that but one bitch from the sixth form team is demanding an apology from me.