Exercise! Lots of it and hard as you safely can.
Journal
Date. Casually. After several weeks.

Never had a pet for similar reasons. But I'm sure there's plenty of people here who could help you out with your unique situation

I disagree. A good puppy will not make you forget about the old one.. but teaching it to play fetch will distract you.
Plus puppy cuddles. Nuff said. ?

I get what you are saying, when I separated from my husband a few years ago I did not wait long enough before dating and ended up dating someone and than letting him move in with me before I really knew the true him. I was so lonely and wanted love so much that I rushed into something that was not right, and it took a few years to get out of that relationship.
I would suggest a support group for divorced people or even a grief group, divorce can have as much grief as a death.

Learn and grow from your experience with the old puppy. Celebrate what you had, grieve what you've lost. When you're ready to move on, you will. You'll never forget the old puppy, but growing from your experience will make your relationship with a new puppy that much richer.

The comparison is the issue here, at least for me. My "old puppy" is one thing, and a "new puppy" will be its own thing. I waited quite a while before I began "puppy shopping" to avoid subconsciously linking the old with the new. I agree fully that feelings are hard. But when there is a massive laceration, bandaids don't help, they make it worse. Get stitches, which also hurt, tend to the wound and let it heal first. It is hard to enjoy a "puppy" while still "bleeding."

You can love your old puppy while still reminding yourself that the relationship was bad for you. Focusing the feelings on hoping the old puppy gets better and thinking about the traits which made the old puppy toxic will help you to move on and find a new puppy who is a healthier choice for you. The new puppy should respect your boundaries, have a healthy attitude towards your friendships, and seek to make you happy even when that wouldn't benefit them directly.

The same thing happened with a former partner. We had 2 cats, an older female which we had for a long time and a new male kitten we adopted. The kitten had feline Leukemia and only lived for 3 years. When he died we had some guests and they found another male kitten to take the place of the one that died. She was furious and blamed me (I did have a hand in this). She said the cat was mine and I was responsible for it. However, later we saw the cat was lonesome as the female wanted nothing to do with it. We went out and got another male cat to bond and they really did and became close. This new cat was hers. Thing was, that when we broke up she took her cats with her and wanted to leave me my cat. I convinced her it was not fair to the 2 cats so she took all 3. Sometimes you have to consider the other's feeling (even if it is a pet).