Yes, there are times when I want to say, "OMG you're a flipping Idiot!" But I must restrain my comments. Because opinions are just words, and words can only hurt if you let them. SO, this being said ... How to deal with comments that might make you mad and give someone a lashing to? Find one thing in the comment that is flawed and LAUGH. No seriously Laugh until you cry if you can do that. (This is how you survive everything)
How to deal with bad reviews? Everyone gets them. Every book. Not everyone will love you. Not everyone will love your book. Not everyone will love your ending. Not everyone will love your characters, subject matter. This list can go on forever but you get the point. There are a Billion somewhat people all over this planet, Just as long as someone likes it, you did your job. That's the point. It would be nice if everyone liked it, but it's fine if they don't. Did they read it or attempt to? Yes. Again that's your job as a writer. So High five. Eat something sweet, watch something that makes you laugh, and then go write.
How to deal with endings not going your way? Outline backwards. Seriously, try it. Outline the book how you need or want it to end. Then work from there until you reach the place you are currently stuck. I was doing this with one of my projects right now. This also helps you avoid writer's block.
How to come up with an awesome title name? I'm not the best at this BUT .... I usually find two or three things within the book that could become the name. Example: Rival Love ... Skylar and Caleb BOTH love their schools. TOTALLY LOVE THEM. They also happen to be Rivals. When the two are stuck under the same roof ... The Rival Drives their choices as well as Love. So that's how I came up with Rival Love.
Happy reading and writing,