I would agree with some posts in here that you can't just judge the OP (at first) cause he said he was getting done for GBH. Now the OP has given the reason for the GBH charge then he deserves what he gets. To bottle someone cause they are doing your head in and winding you up is a poor excuse, would it not have been easier to walk away from this person or leave?
In September 2000 I got in to a fight in my local town centre. 2 blokes were slapping a girl about, so I stepped in to try and calm things down, all seemed ok and the situation calmed and then the blokes turned on me, the girl walked away and I was left with the blokes provoking me. This went on for 10 mins, both lads taking off their coats and jumpers getting themselves ready while I just stood there. After about 12 mins of pure abuse off these blokes I went alpha on them and got them both to the floor and then police came and all of us were arrested. The whole situation was caught on CCTV. I was charged with ABH and Affray it went to magistrates court but it was passed on to the Crown Court as they decided they couldn't give me a tough enough sentence. This was totally out of character for me and have never done anything like it before but one bloke slapping a woman about is bad enough let alone 2!!! Anyway it got to crown court and the judge could see how I had got myself in to the situation but clearly said that the way I dealt with it was wrong and that there were other options. In the end I was given a 2 year suspended sentence and a fine and that was it! He said I was very very lucky and got this sentence by the skin of my teeth.
It's wrong to judge people on a tiny little detail once you get the bigger picture you should then make your assumptions.
To the OP - you may get lucky you may not only time will tell.