Help with USCIS, I aplied for a Honduran TPS (temporary Protected Status) they send me a?

I aplied on october 2009, and they just send me a letter requesting evidence, they say that I send a copie of my pport issued on 2007, and I need to tell them that I coud not get it before 'cause I was under age, and also they want me send them evidence that I habe been here in the U.S since 1999, and I was born in 1988, so in 1999, I was 11 years old, so I do not have anything to prove that I've been here since then, and as you can see I am not good with this, it is going to be hard for me to white them a letter and explaint, so if anybody know what can I do, I will really really aprecciate it, thank you in advance for taking your time helping me!