is it bad to feel that everyone is living more exciting lives than me?

When I was 16, my biggest problem was about love. No matter how well I was doing in school, how great my relationship was with my friends, how little responsibility I had in my hands, my mind was always occupied by thoughts of high school love. Back then, I didn't have to worry about much. School was easy. Life wasn't too hard. I was certain about the future. And I had all the self confident in the world in term of intelligent and capability. So my numero uno concern was about the freedom of having a boyfriend and being in love and all that other teenage hormonal stuff. But then again, didn't we all at 16?
Seven years later and here I am. 23 years old. School wasn't that easy. Life is kinda hard. I don't know my future. And I don't know where all my self confident have gone. I have lots of freedom now, but even more responsibilities. I don't really think about love because my mind is complete occupied with the uncertainty of tomorrow. I semi-plan things to avoid failure, and yet very little works out in the end. Such is now while I am sitting here, unsure of what I will be doing tomorrow, and the next day, and the day after that.
I had thought, no, envisioned about my days of June ever since December when I was told about the program. And thought I had doubts, lying awake at 3 am feeling anxious about the idea of being somewhere in Africa and away from all the simple comforts, I also was excited for the days to come. I keep trying to tell myself that this too shall pass, that before I know it, I will be doing what I want and get out of this eternal slump.
But then I go a read blogs from Peace Corps volunteers and trainess and feel so down all over again. If I don't do it, I'm afraid that I will forget that I want it. But when I do it, I feel sad because I don't know when it will come.
My appointment to discuss my health status (again) at the clinic is Monday.
Listening to One Republic isn't also really helping this mood.