Painting a garage.

[citroen]

My garage has been painted in the past with a water based stain(Ronseal)..Today,I painted part of it with creosote substitute but I must be allergic to it because my face has broken out in red blotches.I want to go back to Ronseal water based paint.How long will I need to wait before I can paint over the part I have creosoted.Or is there some way I can remove the creosote.I would be very grateful for any help anyone can give me.