Sending her to nursery would be best for everyone. Even if it's just for a few days. If she can't go to nursery then I would structure your day like a nursery.
Start the morning easy and take your time over breakfast. Get her to help even if it's just setting out cereal and a little jug of milk so she can pour it herself. Give her a banana and blunt knife to chop up for her porridge. Butter her own toast. That sort of thing. Get her up on a kitchen helper stool to help wash the dishes up afterwards.
Structure the day rigidly with specific set times for story, songs, snack, activities, telly etc. It'll help you stay sane to have a routine. You could even make a little picture timetable for her on the wall to show her what's happening each day.
Have a look online at ideas for ikea flisat table set ups. It doesn't need to be complicated. Kinetic sand with seashells, stones, and various spades and scoops are a big hit with my toddler. Also little toy diggers and trucks. Put a few towels down under it and it can be a water tray- give her various jugs and cups to pour with. Or just fill it with interesting pasta shapes.
Tuff trays are great for this kind of thing too. You can set them up to be themed. At Christmas my son had a tuff tray full of cotton wool balls for snow and little Christmas figurines.
Pinterest is great for easy arts and crafts ideas. Again, it's a good idea to link them to a theme- either a season or holiday or book she currently enjoys.
Empty out the recycling bin and do junk modelling- make houses, castles, car garages etc.
Do you have the space for some things for her to climb on? Our house is very small but we have a pikler triangle and slide. It folds so we have it hanging on our bedroom wall on large hooks and bring it out when needed. He clambers about on that or we put blankets over it to make dens. There are also small sets of soft play cubes etc that all fit together and store quite small.
Have story time followed by some tv time. There are so many animated versions of books now. You could read a Julia Donaldson and then watch the animated version from iPlayer for example. I'd have some carefully timed telly time half way through the day to save your sanity.
Whenever we're stuck at home bathtime becomes a bigger deal. Any toy that won't break in the bath is allowed in. We've had Duplo baths and mega blocks baths and monster truck baths!