I learned to eliminate the two-space-hit after a period by clicking on 'show invisibles' on my Mac. There has to be an option for this on a Windows machine. Once you see the markings, it vastly improves your typing so that the mistakes don't happen in the beginning and you can see them to correct them if they already exist. If you do a 'find' and look for (. ) and change it to (. ), then you only have to go back to the end of each sentence to correct the double spacing. (Except for a pass where you look for exclamation points or question marks. Those need to be corrected separately)
A lot of the criticism about your chapters is also about it being the second book. If she finds the characters to be 'cardboard' then it is worth it to spend a little bit of time on making the first couple chapters worth of characterizations stronger...the advantage of self-publishing. You can learn and improve the work after the initial release.
I'm neutral about the review. It was brutal...that is for sure. I think that the reviewer needs to learn how to function in polite society and recognize that this is a learning environment. Telling someone to take a creative writing class isn't a solution. Who knows what the person teaching the class wants to teach (realize that I took an EIGHT credit Creative-Writing class in college that was only about Black and African History. We wrote three things during the entire class) Identifying weaknesses alongside strengths is a better way of getting a point across. In education, you don't expose kids to 100% new material. You introduce it and build on old skills. There is some study out there that I remember...kids can get about 20% of material wrong without getting discouraged. In the review Miss Bomb-Pop gave you, I see about 10% compliment to approximately 90% negative. No wonder you were discouraged.
In the Beta read I just finished, I told the author about my three-strike rule. Once I saw three glaring novice mistakes, I showed her where I thought an editor would put down her book, knowing that the mistakes had to be everywhere throughout the manuscript. The bad news was that she lasted two pages. The good news is that the things I noticed were easily fixed and had nothing to do with the content.
Bomb-Pop seems to be a punctuation nazi. And she couldn't get past the technical to enjoy the story. That is the key take-home from her review, I think. There will be others who take her stance. Since most of her critique is about technical issues (tags, spacing, and length of the story), these are all easily fixed/ thinned. The only exception is the characterizations in the beginning of the second book, and that is also something you can address in a comfortable period of time (I think).
Take heart. Take what seems correct from her review and make it your own. Discard what you don't agree with. Let your skin be a bit tougher. You want to be a pro writer and support your family from this series, so your skill level at this point in time isn't an end point. Your learning curve is just beginning.
I'm an optimist. I think this is within your reach.
FYI, Who was she? I want her to read my stuff and rip me a new bung-hole as well. Or is she floating around the site and dropping big flaming piles of poo all over everybody's business? Because I like a nice, cozy campfire. Did she dare to post something? If that is the case, I'm going to review her back. When I get old, I wanna be more truthful. Maybe I'll just have to start...right...now:-)