Agree with everything said by @Furries and @PriOn1 .
Puppy blues is a real thing. Please don't be too hard on yourself. I was in a similar situation to you. I spent much of the first few weeks crying and regretting that we had a dog. Before I am flamed for this, puppy blues is a real thing. Looking back, despite all the intensive researching and prep , knowing what you are getting yourself into isn't the same as the actual experience of it. It's a huge lifestyle change.
To get over my puppy blues, I threw myself into training to raise the dog that we wanted. It really helped. It provides a different focus for you and it's also important for everyone to have a well mannered dog.
We've always hand fed kibble from day one. We still do almost 9 months later. We always make her sit and wait for permission before she can eat. As well as the basic commands in @Furries post, training a release word is also a useful one for self discipline. You can do this daily when feeding or playing ball games. E.g. put dog in sit and wait, chuck the ball and dog doesn't go for it until you give the release word. Our release word is "okay". Training self discipline really helps create a calm and well mannered dog.
We do a lot of mental training and enrichment too. Short bursts definitely tires our dog out more than walks. Our breed was chosen because of its trainable nature though. All of this helps to create a calm puppy which means dog is happy and we're all happy.
Get your wife and kids onboard. Hopefully, it isn't all falling on you which might be contributing to how you're feeling. My DH and kids insisted on the dog. I'm pretty firm that we are all in it together and not just the fun times and cuddly times. Even my 8yo will pick up dog poo. They also have to train the dog daily (ours is not quite 9 months so training is still constant). I want the dog to see my DH and kids also as the source of all good things so it listens to all of us.
Before I got my dog, I spoke to lots and lots of friends who had dogs. Nobody ever mentioned any regret but only positive things. Once I got my dog, they all confided that they all found the puppy stage horrendously hard and were filled with regret. Not sure why they didn't tell me before I got the dog but I think there's some shame around admitting puppy regret. Or worries about the responses they'll get especially judging by some of the posts on here.
The good news is that it does pass. They would all say the dog is their life. I only know one person who gave their dog back to the breeder after 8 weeks.
There are lots of FB groups that can provide emotional support and advice too, including from dog trainers. Might be useful to join some? There's likely to be one specific to your breed as well. I found this hugely helpful and felt less alone and overwhelmed discovering that everything I was feeling and going through was shared by so many dog owners. I got a lot of great advice, encouragement and support as well.
We all love our dog so much but, goodness, the first couple of months was so hard!!! If you can, do join a puppy group or find a support group. It really will make it a lot easier to be surrounded by others going through the same stage or who have been there and can understand.