Advice on handling grief/fear among getting new dog

TLDR; I sort of need some advice here about how to handle losing your soul dog in an awful random unexplained manner at a young age, and how to deal with that anxiety with your next pet

For some background: I got Bowie 5 years ago because my sister moved during COVID and I was devastated. My therapist suggested an emotional support dog, and I’ve always known I wanted dogs so I thought it was an excellent idea. I love animals, but especially dogs. I grew up with/around them and just always felt akin to them. My childhood dog was my best friend growing up and quite literally was my protector.
I wanted to get a dog from a rescue but my ex insisted on a specific kind of dog and so we got him from a reputable breeder. I spent countless hours, and love, training him, and continued to do so his whole life. He was my baby, my best friend, my soul dog. He had so many treats, beds, toys, and a car seat. We walked every day and hiked every weekend. He was always by my side, he was my shadow, he slept with me each night. I missed out on vacations and canceled plans to spend nights with him because my happy place was with my baby.

Then he got sick suddenly, he was sick for 3 months before I was told it was lymphoma. I was shocked, the vets were shocked. It was extremely aggressive and progressed lymphoma. A week after we found out, he started bleeding and wouldn’t stop so I had to put him down. That was over a month ago. Somehow it feels so fast but the 3 months caring for him felt so long. I was barely sleeping, super anxious, and taking care of him entirely alone with all his seemingly random issues.

This experience was exhausting, debilitating, life-altering, devastating and traumatic. I would have taken care of him for however long I had to because he was my baby, but it was the worst thing. I thought I knew what pain was, and I’ve been through a lot of traumatic shit in my life, this topped it all. I feel like a part of me died, that he took a piece of my heart and soul with him. I hurt everyday. I quite literally will never be the same and I’ll always want to cry thinking about it. I genuinely am questioning daily how I’m making it through this because I’m surprised I am and I never would think I’d be able to.

But I’m trying to move on and heal somehow. I know I have all this love to give and Bowie would want me to give it to another dog. He would want me to be happy again.
Like I said, I always wanted to rescue, but with what happened to Bowie, even though I know it’s irrational, I’m terrified of getting a dog and experiencing something like this again. So I found the best breeder on the east coast (same kind of dog Bowie was) who does all this extra health testing on the parents and puppies. I put a deposit down for their next litter which is supposed to be in spring (obviously not guaranteed).

I’ve always known I wanted dogs and would have them until the day I die. I actually want two ideally. So I’m hoping to get another once one is 1.5/2ish.

I’m excited but I find myself with a lot of anxiety about it. I feel confident that I can train a puppy as I’ve done it before. I know this dog won’t be my last dog and could be entirely different. I just don’t know how much heartbreak my heart can take is my point.

So if you’ve been through something traumatic with your dog, and got another after. Did you experience anything like this fear? If so, what did you do?