Wow, I have never seen a turtle look like that before. If you have a UVA/UVB bulb on the tank, I would get a new one ASAP. It is obviously no good. Poor turtle. Keep us updated on how he/she is doing!
Hello and Welcome from New Mexico.....How sad....you've come to the right spot....There are plenty of great helpers on this forum as you have already experienced...good luck!