So sorry to hear about your kitty, I had to put mine down a week ago as well and it has been tough, I have a picture of her under my pillow, looking at is a little hard now cause it makes me cry, but knowing the picture is there under my makes me feel like she's still on my bed at night and watching over me, I also set 5 or so mins out at night to cry then I make sure I stop after the time limit and do breathing exercises and put on a podcast. Greif is hard and everyone deals with it differently but I find the days get easier if I have a bit of a plan to deal with it. Hope you feel better soon, it will get better <3