Don't know if this the right message board for this question.

That is a LOT of fear for a young puppy. I would NOT comfort him (although I can understand wanting to). Comforting is not the same for a puppy as for a child. What it shows a puppy is that there was a REASON to be afraid. If you do not buy into it and simply ignore both the noise and his reaction, he will read from you that this is nothing to worry about. The more you buy into his fear and make a deal out of it, the more he will be afraid because you have communicated that to him by reacting. So, counter to the advice above, you CAN reinforce fear if you buy into it. OTOH you can reduce fear by being non reactive to the fear trigger and your dog's reaction to it.

With a child it is very different. You can comfort and explain. Dogs do not understand words and comfort to them is reacting and conveying to them that yes indeedy they were right.. that noise was so scary Mom reacted, picked me up and carried me (like a Mother dog would pick a puppy up and carry it away from danger).

I will also suggest that you talk to your breeder. This seemingly (from your description) extreme fear is not usual for this breed of dog (although this could be a fear period). These are dogs bred to sit next to a hunter in a blind or on a boat and not mind shot gun blasts. My point is, this may be a genetic issue you will need to be aware of for the dog's life.

When you note puppy has a problem with something change how it is presented. If he is fearful of the broom then put him behind a barrier so it cannot attack him. Lay it out of the way so it cannot fall or be tripped over so he can approach it as he likes. Do not go poor pup and bring the scary thing closer or keep it around in the same scary position but respect his fears. If it's a sneeze then try pretend sneezing very very softly and make it a game. He'll still be worried about the big ones but maybe it will be more horror at your rudeness than outright the sky is falling. Rather than picking him up move away from the scary thing. You aren't going to be able to pick him up soon anyway.

You can do some training to get him more accustomed to things. Max was terrified of cars. I clicker trained him to approach, touch and jump into the car on his own rewarding him with a treat rolled away from the scary thing. He got car sick for years but readily jumped in. I was so happy years later when he started asking if we were going for a ride! One time an empty car trailer terrified him, I continued to walk that way but crossed the street, he figured it out in a week's time. Another example was walking down a street where not so nice dogs might be out, he did not want to walk that way some days, I respected that and turned a different way. When Sassy found something new, and she did for a good year after she was adopted, I let her approach at her own pace. She always did but some things took a long time to figure out. A barricade across the sidewalk? It was there for a month and it took her that long to get used to it.

For noises you can expect try a shower of treats. If kitchen sounds are scary then practice them at a lower level with an accomplice rattling things quietly as you toss goodies or offer a plate with a teaspoon of smeared peanut butter. I did this on New Year's Eve and it helped to an extent. Not a dropped pan, try putting a plate on a wood or tile surface quietly at first.

I agree with what's been said. Our Saint has a terrible fear of storms. We didn't pick him up but we do allow him to cower near us. At first, it was an issue because he would attempt to hide behind the computer desk. He would push the thing out of place. Now, if I am at the computer I simply move my legs an allow him to lay down. It's a little uncomfortable for me but it comforts him and he can feel my touch.

I don't recommend heavily babying your pup, supporting yes but try not to lather it on. I do think that if you do go too intensely the pup will learn the behavior even after it's not afraid any more. Don't treat when the dog is afraid. You could try and distract with a training session but he's pretty young.

If you are inside and the dog jumps or reacts try distracting with a toy. It's kind of like saying to your dog, "We don't even hear/see that thing that frightens us because we have better stuff to do."

If it's something he absolutely cannot get over, a lot of Saints hate storms, just try and make him comfortable but don't go heavy on praising or attention. Support not encourage.

Good luck and congrats on the new puppy!