Rejections letters should never be taken negatively. You wouldn't hit a baby, would you? Then why hit yourself in the first ten years! Let me explain.
Most rejections as a group just mean you're WRITING is not there yet. Everyone complains about the process at first, but the truth is you aren't ready to be published until you write and study craft for five years.
Five years...take that in...five years.
Ok now get ready to hear you probably won't be published for another five.
Give the baby ten years and treat your writing like a growing child. Not a particular novel but you're writing as a whole. We all start with one novel. The novel isn't the baby your writing is. Remember to handle your writing with care.