I did the same thing. I didn't know much about dogs at all, and I was so worried about how to be sure they bonded with us and wouldn't grow up to be aggressive, etc. It was alot of wasted energy, my worrying. On the plus side, I was so depressed, I lost weight!!! Weight loss was good, not depression. If I had it all to do again, I would probably still have the crying moments because watching a puppy constantly during the housetraining stage is exhausting. And I felt like I couldn't get out of the house very much because I didn't want to leave him alone for long! So I would go through the same thing again about being exhausted and feeling like I didn't have a life anymore, but I wouldn't worry as much.
I decided at the time that I would never get a puppy again....that I would get full grown dogs from now on!! Two years later, I'm weakening on that stance.