I honestly don't see the point of using paint dissolver here. Most act by vapors that will cause pitting or at least paint softening in nearby areas, so it's somewhat difficult to control exactly where the paint goes away (now or later). If you want to remove the stuff under the paint just sand away the paint and the stuff under. You haven't told us why you "could not sand it down enough to be level with my wall"; the usual hand tool for sanding paint and/or joint compound and/or other types of skim coat is a silicon carbide mesh on a sander. Make sure your sander is flat; the really cheap ones aren't.
And a SiC mesh will easily remove paint (from wall) as well in my experience.
Also, if you couldn't level your joint compound, it probably means you've used one that hardens too fast. So [for future reference] get the 2-hour or 90-minutes variety; also use clean tools and recipients, and get a knife or trowel that is large enough for the area you work on. For your current project, it's probably unnecessary to reapply joint compound unless you end[ed] up with dips. Simply sanding flat what you have and repainting over it should be enough.