Worst mother in the world I am No you're not; you're a mother doing her best in a very difficult and strange situation.
I don't know if you have to pay for it but my children are using White Rose Maths home learning. It's good in that it gives a short video clip introducing the concept and teaching the lesson and then they do the worksheets (8 questions or so only) and the answers are provided.
Writing could be anything: a letter to a loved one or to a favourite character; a setting description using a location they've visited, a Minecraft world they've created or a photograph as a starting point; a set of instructions explaining how to do or make something such as a game or a crafting activity they enjoy; a newspaper report about a current or made up situation; a diary detailing their time away from school.
Science: can you do some experiments such as put a fresh egg in a bowl of vinegar or boil up some red cabbage and use the water as a pH indicator: can they do a write up of the experiment (what we're they finding out? What equipment did they use? What did they keep the same and what did they change? What were their results and what do they show?) Operation Ouch is great for teaching children about their bodies and shows them some cool experiments to demonstrate how it works.
There are some ks2 reading lessons on the Roald Dahl day website: I found one for the Twits.
Tes is free to use and there are a lot of free resources on there - aimed at teachers but can be used at home as well.
For history, google the topic they've been covering at school and you can usually find some video clips and information pages about it. Horrible Histories is great for that as well.
Number and Alpha Blocks on cbeebies is good for maths and phonics at foundation and y1 level.
Geography: draw or find the floor plan for your house/steet-by-street map of your local area and get them to follow it (with you if you're outside) from the start point to a specific end point. When you're on your daily walk (or use Google Maps or google Earth) can you find examples of different land uses (farms, manufacturing, offices, shopping areas, residential, recreational) and try to explain or find out why that particular area of land is used for that purpose?