I had single masectomy almost 5 years ago. After surgery the nurse explained to me what to do with the drain. I drained it myself but mine was a little more difficult because the drain was back a little on my side .
Get some button or zip up tops to wear because they don't want you raising arms over head for awhile.
I had several sleeping pillows that I propped up in my bed to sleep on my back.
If you dont have paper plates put plates and glasses at a lower level so you don't have to reach.
I was able to have my drain removed after a week. That doesnt hurt.
As my yoga mentioned make sure hands are clean .
Thinking of you and glad that person in your life is gone you deserve the best. I had one of those type people in my life once too.
Soon this will all be a memory.
Sending a big hug.