Gles- from part-time to full time almost overnight?

I recently got new gles. I have astigmatism, -4.5 in one eye, and 1.5 in the other and need gles so my near and far vision is clearer. Before I wore them only when I needed to drive or see things far or read. I was never told by my doctor how much i should wear them. But when I picked up my new ones i wasnt wearing my old ones and the man who was trying them on me said "oh, you must be wearing your contacts ". I said i do not have contacts and only wear my gles sometimes and he said that with this the new ones that won't be an option any more, and that I should put them on when i get up and take them off when I go to bed. I tried that for a few days, and now my vision without them is awful, but before I wore them all the time for a few days, my vision was okay without them. What's happening?I don't want gles all the time and cant get contacts because my corneas are too thin for them. Plus, I have bifocals and these have a line, not the blending of myold gles!