You need to get to a hospital fast. If there is a neighboring town or a big city near you, go to one that you havent already been butcherd at!
If you have an abcess in your spinal column, it is very serious and you should never, ever have been discharged! That is life threatening and also if it doesnt kill you, it can and likly will severly disable you!
I am not a doctor but I have seen the affects of spine infections on several people and there is almost nothing that could be that bad! One of the guys I had spoken with was on his 14th surgery to try and remove infection and also fixate more adjacent disc levels that had been infected.
Take this serious, dont wait around to see what happens.