My puppy keeps freezing up and stares at nothing

That is pretty young, I had one dog spayed and she had complications. She started with some weird behavior. I would just watch her very closely. If anything seems very odd like Swaying with her head back and forth, not drinking any water, etc. Bring her to the vet. My dog had ended up dying from her complications. It wasn't the vets fault at all she just didn't take it well. She seemed fine but she would lay around, acted depressed, eventually she quite eating and drinking, an infection set in and she died. She was almost 7 months. Ever since then I have never had any of my dogs spayed/neutered.
Now I know people are probably not agreeing with my decision not to spay/neuter. Normally I don't have two dogs of opposite sex. I normally have male dogs just because they aren't as emotional as females because they don't have a heat. If I have two dogs of the opposite sex I keep them separate especially when I know shes about to go into heat. I have never had an accidental litter. So I have no problem with it. I normally just buy males though.