Hey Debbie!
Keep taking the Paxil - don't give up on it. It takes 2 - 3 weeks for it to kick in and make a difference. I think your back pain is one of three things. It's either because of the kidney infection, sleeping on the couch or just plain ol' anxiety. When we get anxious, we tend to tense muscles without realizing it and those muscles most often are in the back. What part of your back has the pain? Is it on one side and not the other? Upper or lower or just all over? Try doing a lot of stretches and see it if starts to help. It won't take it away instantly, but if you keep stretching a few times every day it will start to go away as long as it isn't pain from the kidney infection. One thing that really helps with back pain is laying flat on the floor with your legs propped up on the couch. Also, if you get on the floor and tuck your legs under your belly, and then with your arms, stretch out as far as you can in front of you without taking your legs out from under you and holding it for about 10 seconds and then to each side for about 10 seconds, that is a really good back stretch. You could also try lying on your back, bend your legs up and let them lie to one side while both of your arms lie to the opposite side and holding it for about 10 seconds and then switching feels really good as well. Try a bunch of stretchs and see if it helps with the pain.
Hang in there! You can do it!