Losing Courage

When I know I have to do something difficult, I usually have to work up a whole lot of courage before I can go through with it. Well as you can imagine, I'm writing this because I have to do something that will be difficult for me so I've been working up the courage and planning out what I am going to say. However, I still have some time before this difficult task and since I've worked up the courage early, I now have way too much time to think about it. Naturally, I start to back down, slowly my confidence fades and my nerves take over. I'm back to arguing with myself as to whether or not I have to do it--the answer is yes I do. But at this point I don't really want to. The fear of what might happen as a result of this is starting to weigh me down. Do I want to do it? no, but I think I will feel much better after I do.