When I first started sending my Java Specialists Newsletter I would get about 10 replies. Of those replies 9 where very positive and they would make me happy. The one comment remaining was by someone not interested in what I had to say. Even though it was not necessarily a negative comment, it pushed me way down mentally. 

You need to ignore haters and accept criticism lightly. If you do this you will continue to improve in what you do without feeling bad about it!