I live in an apartment. Earlier in the year, we had some peeling paint on our front door. I called the landlord, who "fixed" it by simply painting over the peeling paint. It looks horrible and will no doubt peel again. So when paint started peeling in the bathroom, I decided to fix it myself. Oh my god. What I thought was going to be an easy weekend project has exploded in my face.
It looks as though it has been painted at least 3 times. There is drywall under the paint, but there is also a thick layer of sheetrock mud or plaster on top of the drywall-- not just on the seams, but over almost the entire surface of the walls. When I started scraping the paint, it began peeling in large chunks and taking some of the plaster-ish stuff with it. So what we have is several different layers all over the walls. I did a test patch of primer and paint, and you can definitely tell it's not a smooth surface.
I'm getting to a point where mentally and emotionally, I cannot scrape any more paint. I have a power sander, what will happen if I try to sand it smooth, and then prime and paint on top of that? Or should I do a skim coat on top of everything right now? I've never done a skim coat before, but anything would look better than the way it looks right now. On the plus side, the walls weren't completely smooth when I moved in, so it doesn't have to be perfect. I just want it to look nice.
It would be helpful if you could post a pic.
I would skim over the rough areas with sheetrock mud. Use multiple thin coats and don't worry about getting it perfect. Do a skim coat, let it dry and sand a little bit, repeat until you get it like you want it.