No, you are not evil and you are not a bad mother.
You are new mother, having one of those days that all mothers have and which no one wants to talk about. Yes, you need help and you need support and you need some perspective. But you dont need to be labeled--not by yourself or anyone else.
I think therapy is a great idea...but so would a support group be a good idea. See if you can find a 3D group in your area...MOPS, or La Leche League or a number of others. Google and see what you find. If you are unable to get out, there are a number of blogs you can read that will put things in perspective, as well as online chats. I never took advantage of those when my own kids were small, because I raised them in the pre-internet era. You will get a lot of strong opinions on such boards (and in 3D) and perhaps some judgements, yes, but that's what life is like. It will still be good for you to be around other women struggling with the same issues you are.
We are so alone as women when we raise our children. I dont think it was meant to be that way...please reach out to others (and older women, too, if you can find them).
Much love
CB