Some inspiration, I think I would paint everything white, except cabinet and perhaps mirror. I quite like the blue also

The dark painted molding is chopping everything up. Maybe an attempt to balance out the dark vanity? Paint all the trim and beadboard off-white. Make sure the color you pick works with your counter tile. Nothing is really pure white and the wrong paint can make your counters look weird. You could go with any accent color for the walls. The pic above with brown is nice and balances out your vanity. The blue isn't bad either if you keep the brown towels. For a small space, the shower curtain would be better in white. A white curtain will also let in more light from the window behind it.

I would definately paint the room, and the cabinet and replace the countertop. Countertop replacement may not work with your budget. New shower curtain. The black and white tile is great. Cabinet could be painted white, black or a gorgeous gray color.