Inablity to Void - Urine Retention

The ablitity to urninate has become increasingly difficult until last wednesday when I couldn't go at all and had to go to the er. They told me I had an acute UTI and sent me home with antibodics. Two days later - same problem - just couldnt' go! So I went to the uroligist. They were shocked at how much urine I had in my bladder - over 1300cc's. They sent me home with a catheder for the weekend. But to this point, now one can really tell me what is wrong with me. I'm going back in tomorrow for more tests - but I thought I'd see if anybody here as any idea what might be happening for me. I've read that it could be herpes and/or nerve damage on the spinal cord, and/or just a really bad bactiral infection. I would love to hear any ideas anybody might have. I'm frusterated and scared because I don't know what is going on or how to get better.