[neves]

First: read the book "Code Complete" from Steve McConnell. You don't have to read it sequentially, go right to the parts that you have more feedback in your reviews.

Second: take your code reviews as a great learning opportunity. Don't let it take you down. You are probably getting the "Impostor Syndrome", and it is a good thing since you now know that you need to improve. Take the review process as feedback about how to improve. This is Deliberate Practice at its best.