Life with two apple IDs

I have long suffered having two separate apple IDs. The explanation for how or why a second was created has been lost to time. So far ive been family sharing with myself. I thought that would keep me from using the old account, but I constantly run into problems. Occasionally I manage to log into the wrong account on a device or use the wrong pairing (iCloud or media/purchases). Problems with iCloud, my notes, screen time, and other random little stuff that just aggravates me. Has apple come up with some solution for this? Ok, so you can't merge accounts, but can you maybe transfer purchases?

please help this has been going on long enough