Find a matching thick chair rail edging 12 piece and you ll be fine.
Tiling uneven walls shower.
If any part of that should get wet you could have some issues.
You should have used the proper substrate for your shower walls.
Attach a straight board to the backer board along the line.
Just get some chair rail molding or some type of 1 trim pieces.
Whatever you put there you are going to see the uneven tiles.
You still may be able to do it by removing the last tiles and redoing it.
You could have wrapped around the edge w the tiles for a neater look.
When you ended the tiles at the window why weren t they all cut evenly.
This is a dusty job so use plastic to cover your doorways wear a respirator that s rated for dust cover the floor with a drop cloth and make sure there s plenty of ventilation.
Mine is the same way because i used 3 4 thick tile on my wall.
Begin by removing the old tile or the fiberglass shower wall.
When your walls are uneven and you use very thick tile which yours is it s going to happen.
I ended up going w a 1 thick basalt chair rail.
If the shower base is uneven tiles will have to be cut to fit the last row.
This will provide a straight edge for the tile to follow and help support it while it dries.
With the uneven ceiling level you would normally level or laser a horizontal line that runs around the shower enclosure at the top of the tile if leaving a top border tile free see below then measure your row lines down from there to the bottom and start with any bottom trip and cuts and actually place the tile from bottom up to the top.