second guessing?

Ok, I'm not really second guessing anything, I know what I need to do, have to do. I know it essential to my life as a Christian. But I definitely need prayer. As I have been sitting in the hotel last night and this morning, my mind has been racing. I have been thinking about my life when I go back to Portugal. I know that , due to the changes in my heart, my life can't look the same as it did when I left. There are certain changes I need to make. I am excited, very excited, but worries also fill my mind. such as " What if nothing happens as a result of the actions I take?" "What if no one gives a care about what I have to say?" I also know that living among the lost means cutting down on the time I am with my Christians friends. Not abandoning them completely, but I know that I won't be with them as much, which is going to be good. But I am going to miss it so much. I am so used to being surrounded by Christian fellowship. And I guess I should feel "prepared" or something. I don't know, but what if my friends don't understand what I am doing? And I guess a large part of me just doesn't want to give up being with my friends all the time and knowing what goes on, being there ect. Still, somewhere inside I know and I'm excited about what the journey holds. My heart is raging in battle with my flesh. God, I want to be a useful vessle, whatever You need to do, however much You need to take away, do it. I want to be Your light. I'm scared and nervous and I know that I need You to live through me.