I had hysterectomy surgery 4 months ago. i have been having a hard time breathing when i get up to do anything (ok sitting) ct scan shows "there is dependent left lower lobe ground-glass opacity compatible with atelectasis" how do i feel better?

Your Dr will likely want to follow up on this CT finding within a few months. Taking extra deep breaths several times every hour, making yourself cough several times an hour, & staying upright when not sleeping should help some (did they give you an “incentive spirometer” after surgery? Keep using that) If you (or others @ home)smoke, this would be the ideal time to quit, for your lung health.