I'm so sorry - we had cats and rabbits growing up too, and it's so sad when you lose one :(
I have 3 cats now and they all bring me joy in different ways. One curls up on my feet when they're cold if I 'ask' him to and has approximately 3 brain cells, so he's hilariously stupid but loving.
One is aloof and timid 90% of the time until you get in the bath or bed. If it's the bath, then she loses her mind with excitement and keeps you company, chirruping and purring away while you're in the bathroom - she also likes to be my little spoon when I sleep and I think I've accidentally got used to her purring as a sleep aid haha.
And my third cat is so loving and friendly, and whenever I cry (which is all the time because I'm a crier haha), he SPRINTS over and purrs and headbutts me until I stop.
I love coming home to them at the end of the day (when I went anywhere in the day, anyway!) - all three absolutely leg it to the door to say hi and get their heads kissed. And being at home on the sofa with my three sleepy little nuggets is such a direct route to being calm, no matter what kind of day I've had.
I always feel slightly sad for people who don't have pets (although I'm absolutely sure that they would be horrified at the thought! And it's definitely me being sentimental/assuming everyone feels the same as me haha) because they bring me so much happiness and comfort.