Sweetie, a fear of the unknown is an extremely common occurrence. Many, many people feel the same way you do.
When you think about it, it's a life changing decision. It's something that you feel you have to be sure it's the right one. And that can very often put a whole lot of pressure on often very insecure and weakened shoulders. It has very little, if any bearing on who you are as a person, okay?
For some folks, their comfort zone encompasses the way they're treated by those around them. And to illicit a possible change in that treatment, whether for good or ill, is a giant leap outside that comfort zone. It's not surprising you feel scared hon. It's a step into the unknown. Knowing what you want, and getting what you want, aren't always one and the same.
*hugs*
How you should feel is something that's personal to you. Something everyone experiences slightly differently. That doesn't make it any less real.
Take it one step at a time, hon. Find someone to talk to about it. A therapist ideally. Someone you can talk through how you feel with and see what options are available to you.
And remember - courage isn't about not having fear. It's about not letting the fear stop you.