It looks a bit more like velvet to me. Smaller, more numerous dots. If it was me I'd probably ditch TTM and go with CP or copper at this point.
part of my brain don't want to look that way!!
but i also think it could be velvet. Ich would show more disperse white dots and larger one.
but... should i see other fish with symptom ? all i read about velvet is pretty bad and my whole tank should be nuked by now ... that's why i'm hesitant to rule out ich.