I think it may be brook, in which case treating it for ich is pointless. QT the clown for now and start the formalin bath. Check out the procedure here
https://forums.saltwaterfish.com/wiki/formalin-bath
This needs to be done TODAY. Hopefully, you can get formalin. The clown is the only fish that needs treatment for this at this point.
Please post some more pictures so we can positively ID brook. Even so, proceed with the formalin treatment, as soon as you can get your hands on formalin. If it is ich, then the formalin will help with that and we can proceed with treatment of ich. However, if it is brook, then time is of the essence so treat for that now not delaying to figure out what the problem is.