3" Tile Diamond Blade - 2pcs 75mm Super Thin Porcelain Diamond Cutting Disc Wheel for Ceramic Granite Marble Angle Grinder Saw Blade with Arbor 3/8"(10mm)

You can use any 3" cutoff wheel with a 3/8" (9mm) center hole. I like these for tile: https://www.amazon.com/dp/B0B7VK4MTM These are slick for metal https://www.amazon.com/dp/B08C77DFGX

Uhhhhh OK so, first suggestion, find a good creative tile guy and have them come "fix" it. My suggestion on fixing cleaning it up: Start by neatly cut the face tiles to make a cleaner square. Something like a 3" tile blade on a cutoff tool perhaps. Then clean up the cut edges just a bit with a finishing stone. Get some edge trim (or even some bullnose tile) either square or rounded with a large enough profile to cover both tile edges. Cut off the flange that would normally go under the tile, and glue it in place with someting like Wedi or Hydroblok sealant. You could use thinset, but that might build it up more than you can afford it to, and the thinset probably won't bond very well to the edging. Grout it in place and move on with life for now. Lesson learned for next time. Going forward: I don't know wtf you were using to cut that tile, but I will suggest finding at bare minimum a used tile saw off marketplace. Even a harbor freighter. Take your time and be as clean as possible along the way. One row at a time. Measure carefully, use a new sharpie. Back butter large tiles. Keep a damp sponge, wipe as you go. I had more to say, but honestly just get on youtube, watch some videos,