How long does cancer treatment brain fog last after surgery?

Diagnosed with early stage breast cancer 12 Aug that had metastisized to 1 sentinel lymph node after breast biopsy. Breast oncology surgeon ordered PET scan that was originally denied by my insurance until surgeon appealed decision. PET scan found breast cancer as noted + enlarged uterus suspicious for endometrial cancer. Breast surgeon urgent referred me to gyn oncology surgeon that I saw within the week for endometrial biopsy. Diagnosed with endometrial cancer on 08 Sept. Breast surgery to do lumpectomy + removal of 6 lymph nodes done on 11 Sept and radical robot assisted hysterectomy done on 29 Sept. Both surgeries were done as outpatient procedures. This week I met my oncology drs. Waiting on oncotype test results to decide on chemo or not before radiation and hormone therapy. Today was the first day in last 2 months that I feel like myself a bit and not like I’m moving through a very thick fog.