Ich comes from stress. Think of it like a cold. We all have it but our bodies can keep it under control until we become stressed and weakened.
So now that it is in your system it is hard to remove. The best way is to no add anything for atleast a month.
Ich has a life cycle thatis a hard one to nail down. But I would do a WC in 2 weeks and make sure you lighty syphon off the bottom of the tank.
(the cysts will pop and the 'ich' will fall to the bottom to continue the lifecycle, this is about your only chance to remove some of it)
Good Luck!!