I feel for you, I couldn't live in shared house like that, I tried it when I first left home and coudnt get it to work out, I was lucky enough to have the weekends where I saw the no Mrs atm but aftre my secomd housemate, a long standing friend went totally loco on me I vowed never to try it agaim,. I had to rent the cheapest of studio flats but it was bettre than have to live in shared accomadation for me.
I dont know what you do but that salary sounds pretty achivevable in most places with a little experiance in somthing, if you can get £15K for the lowest jobs at Saibburya at 40hrs a week then £20K sounds hopeelsewheer even of its not really what you want to do to begin with.
Belive me there are advantages to shitty jobs, (not saying you have on now I've no idea what you do) in that that they are easily left behind, whe you have years put in somewhere and a half decent salary it can be quite a bit deal to let thta go nd jump inot the uknown. Feel the fear and all that