Totally understand your predicament LG but please be careful!
Is a single bed flat out of your price range? Because something like that would make things much simpler. London prices are insane though, I know. Maybe you could move out to the outskirts of the city or into a relatively nearby town. Prices start to fall then. Its a really crappie time to be searching for a rental home though. Full time jobs not covering the cost of living. Getting a room in a share house is always mega risky. People generally fall out and if you're struggling with MH problems that's an amplified problem. Not to mention the people that come and go and could predate the vulnerable.