www.medisave.co.uk mate
itll cost a little but its safe and discreet
(sorry extreme i know its kinda advertising but i guess there not going to pay for ad space anyways lol)
have a look on yellow pages
www.yell.co.uk for something drug support related in your area. you may even find needle exchange. but there will at leats be some kind of advice line.. they will have details of needle exchnages.. just ring them and pretend your a druggie and ask where your nearest exchange is.