Hi there. I notice that a new post has gone up in Working in Spain section by a French woman. Some of the replies mention websites you may found useful. In fact I made a search today on infojobs.net just using ingles as searchword. Quite a few different jobs advertised, including a Telephone operator that specified they required British people. Of course the rewards for working in a (I presume) call centre are probably not that lucrative but it may give you time to make contacts here and get a better job.
May be worth talking to the journalists at InMadrid magazine (you know the one left as a freebie in all the Irish pubs). They may know of clubs that are on the lookout for new DJs. In fact my best advice is to seek out and talk to expatriates who have been here a while to establish best way of progressing.
Finally don't overlook advertising yourself in copy shop notice boards here (may be worth leaving an ad also in the Booksellers bookshop in Calle Jose Abascal, where people head to to buy English books, magazines etc )
Good luck - I'm sure all on this board are rooting for you!
An English Bookseller in Madrid