Hi Mistere, I agree with the other posts - you're not weak, just in a very difficult situation and the fear of any dominating concern without good advice can feel like too much to handle.
Excellent advice from the others the only other thing I might suggest is visiting citizens advice:
http://www.citizensadvice.org.uk/Think being proactive in this situation might help alleviate some of your fears. I'm aware you suffer from SA and Agoraphobia and this might be worth explaining to anyone who offers you an appointment you feel unable to make. If you feel up to it or someone you live with is able to accompany you here is my experience of the 'drop-in' at the Citizens Advice at Hove town hall:
Get there early - say 8.30/8.45 - the queue starts early despite them not opening till 9/9.15 - you're then allocated a number for a 1:1 with an advisor - Note they only have 15 appointment slots so it's worth the queue. They give good impartial advice and will give you a further appointment if they feel it's appropriate which it sounds it is. They were able to signpost me to a specialist debt agency (payplan.com) who were able to clearly explain a range of financial options available about debt.
Hopefully one or more of the routes we've signposted will open up some choices and alleviate some of the anxieties. Stay strong and try to recognise this as a
temporary situation. I know from personal experience how hard this must be for you and please try to have faith that things might not be as bad as your imagining just now.