I can really sympathise with the OP here. We waited until the dses were 12, 14 and 16 before getting a dog, and it is still bl**dy hard work. The chewing does get better - our lab puppy is 9.5 months old, and does a lot less chewing than she used to. At least all of us were old enough to know that if we left stuff within reach of the puppy, we had only ourselves to blame if they got chewed - a baby can't understand this, and it adds to your workload.
Labs do learn fast - you can do lots of training at home, using treats (labs are very food-oriented and are bright too). Perhaps you could work with the puppy on getting him to drop things on command - give him a toy, tell him to drop it, and offer a treat - when he drops the toy, say 'drop it', praise him and give the treat. Repeat until he learns it - this might only take one or two sessions.
You can work on simple commands like 'sit', 'stay', 'down' etc in a similar way. For example, tell the dog to sit whilst pressing on his rear end so he sits - say 'sit' again, tell him he's a good boy and give the treat.
When he's learned sit, you can teach down by gently pulling one front leg forward while he sits, or by holding a treat down at floor level so he has to lie down to get it.
Teach him to offer a paw, by saying paw and picking his paw up whilst he is sitting.
I am telling you all this because as well as excercise, training and learning will tire your pup out and make your life easier. But I realise that this is a huge amount of work, and with a small baby, you already have a huge workload, so if you decide that this is too much, I, for one, would not blame you.
How would you rehome the dog? Via the breeder or via a labrador rescue society? If you need advice on this, Vallhala is very knowlegeable.