Stuck in the breastfeeding doom loop at 7m, trying to wean

I have been an "over-supplier" since day 1. Since returning to work at 6m, I've tried to wean myself & baby, supplement with formula and cut out pumping sessions. It's been over 4 weeks and I am still seeing no change in supply. When I do pump, I only hand-pump with my Medela, letting the Spectra collect dust. As soon as I think I'm starting to get less engorged and can sleep comfortable thru the night (6-7h stretch), I'll suddenly find myself right back at square 1. My ideal is 1 nursing session at wake up and bedtime with 1 pumping session mid-day (3 total in 24h). Has anyone accomplished this cadence? Is this a pipe dream?

My son still wakes up to feed in the middle of the night 2x (12 & 4) and when it's my night "on-duty" I nurse him... is this the culprit? Is this little super sucker really making that much of an impact every other night for those 2 feeds? The bugger!