Confidence is Oh so fragile

Its quite terrifying to find that we are so vulnerable,and our confidence can be knocked so easily.(I say we, I may be on my own in this!)
I had until very recently been quite proud of the fact that I have raised well over £1000 for Leukaemia and Lymphona Research, mainly through pattern sales on Etsy, and more recently through Folksy and Ravelry. It had given me a reason to continue the design process, the structuring of a project that I love so much. But a few days ago someone contacted me to say that although they like one of my patterns, they thought it was wrong of me to charge for it, as it was a basic pattern and there was a free version available.
Since then my confidence, not just in my designing, but in everything has been dashed. Nothing that I make or do seems worthy anymore.
I have always tried not to look at what else is out there, but just to design whatever pops into my head. There is so much available on the internet that if you spend time looking at other people's work you would never come up with an idea that you felt was original.
But the big question is - should we charge for patterns? For some people it is their livelihood,(as it was mine, at one time) and any author of a pattern book will include projects for beginners - people still buy them.
I had been looking at it from the other perspective - I saw it as a way of raising money for my charity, a way in which people received something in return for their donation. I do need to point out here that not all the money from sales goes to the charity. I have to take out the selling fees, the cost of materials and any other expenses incurred.
But now I am questioning everything I do - and I mean everything
My confidence and my happiness has taken a serious knock. I am not sure I can put any more patterns up for sale. The joy has all gone. My raison d.etre was always fragile - now it's in pieces.

If you have any comments, either from the designers perspective or the buyers point of view, I would be like to hear them. I might not like what you say, but I can't feel any worse than I do at the moment