I had white spot or ich whatever but it took me a long time to get rid of it as well as i was just starting out, someone told me to put the temp up to 30 and cover the tank cant remember the reason for covering the tank something to do with the free swimming ones, i also did water change every 3 days to let the treatment have a chance to work then did water change and treated again, I use meth blue or something and that worked.
I have read that too much treatment can make them infertile dont know if that correct or not.
Hope you get it sorted