Thinking of you.Hope it's going okay.
I remembered a few more things that have worked for us.
One is : playdough / oats/ 'clean' cereal / rice/ pasta + small toys/ cars/ plastic animals/ toy trains. The combo of a familiar toy with a new substance is a winner.
It gets messy though - so put down an old sheet or lots of newspaper so you can clear up easily. Use plastic boxes or a tea tray to contain the cereal or whatever and let them play on that.
(For the cereal - do NOT use Coco Pops or anything sticky! Rice Krispies or Cornflakes are good.)
Also - put a few drops of food colouring into water for water play. Or just into their bath water. You can add another colour later- eg. red and then add blue - it's fun to see the colour change.
Get out a box of sticking plasters and some bandages and let them play nurse to some dolls or teddies. Watch that CBeebies doctor programme first to get them in the mood.
Indoor snowball fight - using scrunched up paper or cotton wool balls. Watch a snowy Peter Rabbit - I'm sure there's a snowball fight one.
Also - mine love it if we clap and chant their name while they run across the room and jump onto the sofa then do a victory salute raising their arms. They would do this until I was hoarse if they could.
Come on! You can do this.