Seriously?!? I am only 22!

I must have the worst luck ever. I am very aware that there are people out there that have it worse than me. So I am still taking antibiotics for my tooth. I got the first half of my root canal done last Tuesday, and I go back to have it finished this coming Wednesday. My back has given me problems for the past couples of years, but lately it has gotten really bad. I will be nauseous and cannot stand the pain is so bad. So I went to the Dr. on Tuesday to see about my back. Turns out I have a nerve in my lower back that's messed up. The option that makes it flare up is the walking motion .... seriously? I wait tables. My job is to walk around for 6 hours at a time.  What am I supposed to do? My bills have to be paid so I have to work. The Dr is putting me on a 6 week regimen of celebrex and a steroid based anti-inflammatory. Problem is I can't even start that til I am all done with my tooth stuff. Because I am still on the antibiotics, and steroids will mess with the healing process and make the antibiotics less effective. By the time I am off work I curl up in my bed and practically cry myself to sleep. It ridiculously pathetic. I just don't know what to do! The situation overall is stressing me out! I am too young and much too broke to have health issues that effect my work. I just need to find myself a nice little job where I get to sit all day, and that involves limited mobility. Anyone know where I can find one of those?