I kinda disagree on the last point. Barry has three realizations in my opinion.

First one is that he is too emotionally attached to his previous timeline and the memories he had and couldn't just see them wither away and just leave them out completely.

Second one is that Barry realized that the lives of many people he loves are just shit now and miserable. Barry couldn't be happy that something that is related to his life and that should be only affect him, is affecting other people he love. What I mean is, Barry's mom and dad were killed, and that he felt he has to own it instead of doing something that affect others in a negative way and they also have to carry it out in their lives too. 1 is enough and he just needs to accept that this is his curse to bear and live with.

Third one is... Barry just loves being the flash. He can't lead a life anymore when he isn't the flash. I think he hated the idea of him forgetting who he was and what he has built over the years and just settle to a normal life that he hasn't lived.

This is why, the hero Barry, chose to just undo it all, and hold on to his flashpoint memories and the 3 months that he has lived with his parents and to know what they are like and what life he could've had, which is a cool side effect of his superpower. Instead of asking what if, you can live the what if, and decide for yourself. But he is just stupid with time travel, at least till now. He's still learning.