In no particular order, and to be added-to
It's OK to be sad, angry, despairing, disorganised, untidy, extravagant, frugal; to sleep late; to get up in the middle of the night and read; to garden all day and get really dirty; to sit in your armchair and snooze; to go out and party; to stay in and sulk...
Don't let anyone tell you how you are feeling. They really really don't know.
When they ask "how are you both?" my answer is usually "he's still dead" (John's answer at the end of his life was "Still dying" which has to be the best conversation-stopper ever...) - if you aren;'t sure "How are you?" is plenty...
It's your house now - shrine it up if you wish but don't feel obliged - I discussed the changes with John before he died, somewhat to his surprise. The big bedroom became my workroom within a couple of weeks, and the little office that was his is now my Post Room and was the first thing I remade. The little sewing room is a cosy bedroom and I'm happy there with the cat snoring next to me. The cupboards got turfed out and re-arranged, and all his odd foods went to the Food Bank or the compost. I sorted a lot of books and tools for sale and firmly disposed of all the scruffy clothes
Talk about him, don't let him slide into oblivion. He was lovely, and irritating, and selfish and selfless, and you miss him, so keep him in your speech and heart
Yes, doing all the bloody jobs is just dreadful, it was so nice to come in sometimes to clean dishes and a cooked supper. Having to take out All The Rubbish and Sharpen All The Knives sucks.. And knowing that if you don't hoover it or pick it up no-one else will also sucks
Do try to keep eating properly - I did well for a year, badly for the second year, then better again... The temptation to live on buns was tremendous but damaging
Talking to yourself is a good idea. Shouting at the walls occasionally, also a good idea, doing it all the time is hard on the voice
Get out and about. Even in full lockdown I went to the Post Office twice a week (I like to eat) and spoke to people in the supermarket and in cafes. Sanity was helped. Lack of physical contact was the hardest thing, but I really do not want a lover, however nice. Men my age want a housekeeper, or a Nurse With A Purse...
I'll add to this later, perhaps. Prompted by having an operation on my thumb and then being single-handed and one-handed all at once for two weeks... Self care sucks, too...
* and maybe for widowers too, how would I know?