Interview woes

I had an interview today for a job that I really really really want to have. ARRGGHH.. if only I knew how to express how I really want this job then maybe I could've left a more lasting impression to the interviewer. I feel so dumb. I seriously don't know how to act during an interview. After an interview, I tend to criticize myself for being to quiet, being too timid or being too shy. I hate hate hate those qualities.

I really want this job. I seriously don't care about the amount of money that they will pay me. But why am i ranting here?? I should be saying this to that person.

Sir, if you're reading this, I really really do want this job. I'm sorry for being so timid earlier, but I just did not want to come off as being too aggressive and too informal.

ARGGGHHH!!!