DietCokeIsBae perhaps you would like to do something that you haven't been able to do for a while, something that you wouldn't necessarily do at home. So it rules out cooking,
Something different to what you would usually do, for instance going alone to a place of interest, museum, National Trust building, cinema (time permitting), some little pampering ie manicure (I'm not implying it might be unusual, I'm just writing some pampering ideas that I have, for myself
).
Depending on where you live, you could perhaps go to a neighbouring borough or town, or resort, and take it from there. Change of scenery also feels so refreshing sometimes, even if it's only a coffee shop and restaurant but in a different area. It's great to have a change from the routine.
Weather is set to be pleasant in all over the UK tomorrow (I think), so it opens up more chances for a pleasant stroll and picnic & meal in a different park- lake-woods-scenic settings in a different area.
If it doesn't feel like too much of a hassle, perhaps you could do the crochet & good book & nice meal ideas in a neighbouring town. A very quick search on the Trip Advisor or local tourist board website to find out about the best parks, attractions etc in the nearby places. As if you are a tourist to the area.
If all these fancy ideas fail, still I'm sure you'll get the best out of your free time by being alone with your creative hobbies for a few hours in your own city.