Sounds just like bifocals.
It took me 9 months to get used to them. And they were my very first pair of glasses. I took them back 12 times and had my eyes checked 3 more times. Each and evry time it showed the glasses I had just bought were 'right on' for my eyes. I went to 2 other Dr's. also. My Dr. said ''one day you will just not notice you have them on.'' He also said it would take about 2 weeks. One day 9 months later (I could have had a baby by then !!) I got into the shower and they fogged up. WOW, I had forgot I had them on. I am used to them. That was 3 pairs ago. Every time they change the prescription it takes a few days to adjust.
But having said all this, I did get a pair from Sears that was the WRONG prescription. The had left out one numer and I couldn't even see through them. Just go back and get your eyes rechecked and go from there.
Good luck.
Katz