Single in-ear is a no, hell no, not happening thing. Your brain can't process disparate volumes and you crank up the monitor to hear it while all the racket has full access to the other ear.
I am guessing you aren't using any earplugs as yet? I recommend the comfy foam tipped metal ones from flareaudio.com in UK.
Damping down everything makes it easier to hear everything way better, including myself. Might be all you need.
If that's not enough I would tend toward a practice amp with a tuner out that you could put on the floor at your feet laying right back. Tuner out goes to stage amp.
Turning its bass right down it will get loud enough to hear what note you are playing, with minimal interruption to life in general.
Plop down, plug in power and string cable back to stage amp. Sound check is plucking an open D and bringing it up with your fretting hand. You should be ready before the drummer has shifted the kit into place.