I had a similar problem with my shower. The original installation was an epic fail because it wasn't sealed completely. I had to remove all of the glass. If you face the shower "door" there is a half-wall on the left. There was a long, thin piece of glass on the left of the entry and the door was anchored with a piano hinge on the right. The whole thing leaked. When I removed the metal hardware,
green water flowed out and down the drain. I kid you not.
Since I had two walls to protect (the entry and the half wall), my fix was a bit unique. I anchored one of
these flanges on each wall; one on the wall above the entry and one above the half wall. Then I screwed one of
these adapters into each flange. Into the adapters I put some PVC pipe that stretched to the beginning of the half wall where the pipes almost touched at a right angle. I then put a three-way elbow fitting onto the PVC pipe and another piece of pipe going down from the elbow to the top of the half wall. I put a rubber boot (chair leg cap) on the bottom of that pipe so it rested on the half wall. Then I hung two over-lapping shower curtains on the PVC pipe. When the curtains get dirty, I wash them. When they get worn, I buy two more for cheap. Easy.
My recommendation is to use one of those adjustable shower rods. That should work. Cleaning the curtains is easy and replacing them is cheap.
