Why are fridays so hard?

I lost my son 1.5 months ago on a Saturday. I replay Friday and the week before in my head over and over hoping to do something different for a different outcome. Sadly and unfortunately its impossible. I feel like, I have been looking for an answer that I wont get, at least in this short period of time. Why are Fridays so hard, gut wrenching pain every week and im unable to keep it together. Anyone else have a hard day out of the week? Have you done anything to help? My therapist recommended to write down and burn all the what ifs and guilt I cant seem to get over. But im also afraid to loose these thoughts as i feel like ots keeping me connected to my son.