Need More Space!

I moved my Mom in with me and my son 13 months ago. It was two years after my Dad passed away. They had a beautiful condo on the river, but it was too large, and the landlord really wanted to sell. My home, directly on the beach, is actually too small. It is only two bedrooms. I’m disabled so I sleep in a medical recliner. I gave the master to my Mom, my son stayed put, and my living room became my space. It’s only 1,100 sq. ft. My Mom was physically better off than me, so I expected a couple of home cooked meals a week for my son. I have so much wrong, I can only have Boost liquid meals, yogurt, and corn and rice cereals. I kept my housekeeper but brought the frequency with which she came, to once per month. Mom still drove; stores, hair dresser, and doctor appointments. She shouldn’t have been. Going 10 miles under the speed limit is just as dangerous as going 10 over. I went back to having my son drive me. I made a decision five years ago to not drive anymore. I was on some serious opiates for chronic pain and I didn’t want to pretend my meds weren’t affecting my driving. Mom and I have always had a great relationship. But being in tight quarters was wearing on everyone. I rent. I really don’t know how to fix the problem of adding new space to the existing structure. Does anyone have any ideas?