Dogs are great, I love dogs
But I'm a bit scared, when I'm too low, I can't take care of the dog.
I think there are some small dogs that you don't need to walk as much if they have enough space to run around.
I'm not sure if a cat could also be an PTSD support animal, but maybe. Certain breeds are more affectionate than others.
I think there's different levels of support animals. Getting an ESA is a lower standard I think (at least in the US). To get an ESA, you just need to have a letter from a healthcare professional, I think.
I don't think you can take an ESA on public transportation or in public places though. The ESA designation will let you get a dog in an apartment, even if the landlord says "no pets", because the dog would be an ESA, not a pet.