What to do when everything is too much?

I’m 21, my mom died a few months ago after a 5 year long battle with cancer. Now my dog which is a nice memory of my mom, he’s having a stroke. My dog was with my mom all the time during her sickness, even at the hospice he would move in and the nurses loved him they called him the hospice dog, even other dying patients loved him and he would be borrowed from us, to go to other patients rooms and relax them. I’ve literally had him since I was 7 and I just don’t wanna lose him now that I just lost my mom, who was my closest, and then probably my dog is my second closest. Why is all this pain coming down on me at the same time. Also I just became a mom to a 3 month old kitten which is kinda stressful also, because I don’t know how to take care of him the best when all of this is going on, I do try my best with him though. I don’t know what to do. I can’t stop crying I don’t know when this bad luck will stop. How do I keep going when I just want everything to stop. I can’t breathe