Hehehe, I'm sure you'll be okay! I was like that too when I first started to RP here -- I used to think I was doing a poor job and it made me think hard about what my character would do in various situations, but my peers said otherwise -- so perhaps it's the same to you. My advice is to give it some time, and the character reactions and such will get better! ^^ Kinda like an aged wine or cheese.
Although, I'm not on Mateus -- I wish you the best of luck and I believe in you, friend!
Although, I'm not on Mateus -- I wish you the best of luck and I believe in you, friend!