Here is the CPS sentencing page
http://www.cps.gov.uk/legal/section15/chapter_ p_09_03.html
6 months is the maximum - you can read the aggreavating and mitigating factors for yourself.
You know the details but given your history you're likely to be seen as a danger to the public.
Do you know what an IPP is? It basically means you get banged up and not let out until you can show you're no longer a danger to the public.
http://www.cps.gov.uk/legal/section15/chapter_ r.html
If this had been a GBH with intent you might well have gotten one. That's a very very long stretch.
Don't take my word for it though. Talk to your solicitor about what would have happened if it had been another GBH, ask him about IPPs and have a real long think about what that would mean.
Then, if you haven't already look at anger management and/or alcohol councilling (I'm guessing here but booze is involved in a lot of violence cases)
It'll go down well with the court if you're seen to realise that you've got problems and are trying to do something about them.
It also might just keep you from ending your days inside think of this as a last warning not a luck escape