Oh man there is so much to take in where do you start?

I have four beautiful healthy boys and would desparately love a little girl to complete our family. We havent started trying yet as this is our last chance and I really dont want to get it wrong. I have bought the opk and Ph kits from ebay and have read up a little (so much info) about diet, supplements, books etc.

On a personal note though I need to be in the right head space for this and I dont think I am just yet. I have just found out my brother is having a little girl and I am very jealous. Happy for them of course but I want it to be me. My last son was supposed to be our last and I was upset for days when we discovered he was a boy. Dont get me wrong I love him to death and cant imagine not having him but I am really scared of my reaction if we have another son.
I am incrediably grateful for my boys and their health but I cant help but think of the little girl I want so badly.
Does anyone else feel this way? Scared to get pregnant but scared not to?