Nappy changes I found easier with my 1.3 year old when I placed he hanging mat up against a wall and rolled him to face the wall with a toy. Then elbow on hips or back to keep him there and other (good) hand furiously wiping like my life depended on it!
I found I could lift legs with my good hand to push clean nappy under with my broken hand.
I lifted him using my elbow under his armpit with the plaster side.
Kept to clothes without poppers as much as possible because he is such a wriggler.
Food-wise I did internet deliveries and bought microwave mash, rice, chopped onions and peppers, sliced bread, sliced carrots, grated cheese, diced chicken etc.
I opened packets with teeth or scissors, and kept all the bottles and beakers for my DH to open at the end of the day.
Washing up had to be one handed and was a real pain. Bathing my 4 year old was fine as they're independent enough at that age to at least get in and out independently.
I bought a plaster cast protector from
Amazon which made it possible for me to do the elbow manoeuvre for my 1.3 yr old in the bath too, but most of the time I tried to get someone else to do that for me as it hurt.
I got out to save us all going crazy. My 4 year old scooted and I found the pushchair with a bar easier as I could place my good hand in the centre and I google-earthed my local streets to find routes with even pavements so the pushchair didn't tip. I found my lighter pushchair with two handles no good as I couldn't steer using one side only.
I mastered hair washing and shaving one handed but wasn't perfect, same with using the hair dryer. Luckily I got a Braun brush dryer last year and it's reasonably ok to use one handed.
Expect to be tired as doing everything one handed is a HUGE effort.
Try to move fingers and thumb as much as you can within reason (not causing pain) so you're not all stiffened up when the plaster comes off.
You have my sympathies, it was a dark 6 weeks for me and I am still not yet fully healed.