GBH Section 20

[willston]

I've been charged with GBH Section 20. Driving through my town centre a bloke spat at my car, I got out of the car, he ran at me with his fists up so I punched him in self defence as he was going to hit me. He fell back and banged his head on the road. He suffered a broken cheek, broken eye socket and a fractured skull. I told his wife to ring an ambulance then I put him in the recovery position. I then jumped back in my car and drove off. I was arrested next morning for GBH Section 18 but they lowered the charge to Section 20 after viewing the CCTV.
I pleaded not guilty at magistrates court, it has been referred to crown court where I will plead not guilty (on my solicitors advice) and from there it will go to trial around August time.
Does anybody have any advice or have been in similar circumstances?
I have had a look at the sentencing guidlines online and the starting sentence in 24 weeks inside. The minimum is maximum community service and the maximum is 36 weeks inside.
I have no previous convictions apart from a minor public order offence in 2008.

[Mike25]

Have you seen the CCTV footage yourself? Does it show the victim running at you with his fists up? If it does then i think you have a good case for self defence and this will convince a jury that you felt threatened. If it doesn't and the victim and wife say otherwise then its a different story. They might say that no-one spat on your car and you got out and verbally abused them for no reason and then he ran at you as you provoked him!
Is there anymore witness? Do you know these people? Do many unanswered questions.

[willston]

Mike25

I have seen the CCTV, it does show his head turn to my car, i get out, he runs at me, it doesnt clearly show his fists up though.
My wife saw it all. Even the CID says he can see why I hit him