As a mouse

Recently, our group is busy preparing our variety show. I am very appreciated to act as a mouse. However, I am not good at acting. Therefore, my mouse is really do not like a mouse. It is so rigid. I hope it can be still a little funny. I am so stupid that I never realized the excellent skill of the actors in movies until now I myself have a role to act and feel it is so hard to do, even just a little mouse.
Maybe in order to understand my role Jap, the lovely little mouse, more, I try to look at the world through his eyes. Always, he stays in the hole where it is safe for him. He goes out for food when he really needs it and tries to keep away from the cat. When I realize this, I am so surprised that I indeed have a lot of similarities with him. Always, I stay in my own world where I feel reliable. I go out to touch others when I really have to and try to keep away from those whom I think are really different from me. Actually, I do not have to act, I am him! Finally, I realize that what matters is not that I cannot act as Jap but that I cannot be myself. There must be something wrong. How can it be that I cannot be myself? I start to wonder that maybe I am always like this that I am living as a man who is not really me. This time, I need to act a role whose characters happen to be the same as me, so I feel so uneasy to do it. It is hard for a man who is used to live with a mask to exactly be himself.
I am a little confused.