Worried Mum to 28 year old son - 1st Psychotic episode and undiagnosed Mental Illness (Schizophrenia?)

I am new to the forums and this is my first post. My son returned to live with myself and my husband (his step-dad) around 9 months ago. He'd been living with his Dad for 9 years (and struggling with social anxiety/depression and computer game adddiction on and off) as he didn't want to be home anymore when he turned 18. We knew things were very wrong as soon as we got to see him on a day to day basis - this culminated in him being admitted to Psych. ward in December with a 1st episode Psychosis and a possible diagnosis of Schizophrenia was mentioned by the hospital Dr. He's been home again now for approx. 4 weeks and things have been tough! We've experienced times where we've felt that its unsafe to leave him at home alone, eg gas left on, doors left unlocked etc. This seems to be a little better at the moment. He has obviously not been functioning properly for quite a long time, which has resulted in him having a lot of debts, no friends/social life, no car as he couldn't afford to fix it - and his life in a bit of a mess. He does have a couple of casual jobs that he can hopefully return to once he gets clearance from the Dr. (hopefully) Our main concern with him at the moment is his addiction to computer games (World of Warcraft) which drags him in and he spends a lot of his day locked away in his bedroom. We've tried everything - but I've now given up as he doesn't seem to want to quit even though we can all see that this is really unhealthy for him. We've just started to reach out for ourselves and try to get some community support/carer help - but I honestly don't really know where to start. We feel like our lives have been taken over by this and I don't really know a way out. We just want him to get better and lead a happy life - I hope this is possible. Thanks for reading - any tips/support would be appreciated.