I'm overwhelmed with the responses and the sharing of personal experiences, there really are some great people on this forum. I can't thank you all enough, I wish I could do it individually or even respond to all the posts of support. I'd love to take you all out for a beer or two Welshy; I presume you're Welsh if you are ever in the Gower area I'd love the chance to buy you that pint mate.
Small update. Overnight he's said if I can't or won't support him being his guarantor then he wants no further contact with me as he doesn't see me as his father as no father would treat his son like this. I know its a shock tactic to try and make me buckle but I'm staying strong in my decision. I'll let the situation calm down for a week or so and attempt some sort of contact then.
Thanks once again.