You have to have a thick skin if you are going to be a writer. People are going to correct your grammar and write you bad reviews too.....nothing you can do about that stuff. But while you're down in the dumps about it, you might as well self-promote too.
Some people get offended at the slightest promotion. You're going to have to ignore them. I offered free books to people before, just to get the word out about my novel, and I found people on another thread talking about how they can't stand it. I apologized, told them I would even give them a free copy for the offense, and I was scolded telling me I turned their post into a commercial for the low, low, price of my book.
If these complainers had it their way, I guess my book would cost $50, and I would never mention it. You can't please everyone, so gently offer your book to people, if they hate you for it, then you don't need them as readers.