Life questions

Lately I have been thinking about things in my life that I wish I could change. People I have dated or had more than friend feelings for, things I have done that I'm not too proud of, things I have said. Some of these things have made me stronger, but other things have left me with disappointment. I also think of people who have let me down. I feel as if sometimes it's the ones who are closest to me are the ones who have let me down the most. Have I done something to deserve this? Was it something I did/said? How can I ever live up to others expectations of myself if they can't live up to mine? And why do I feel as if I will let down the people who have never let me down. Is that fair to them and me? Or am I just a confused teenage girl who doesn't know what she truly wants in this thing called life. Sure I hopes and dreams, but what if they are only going to be hopes and dreams. What if I am supposed to be doing something totally opposite of what I want to do. What if I wait for something that could possibly never happen and I miss out on something great. Is that fair to me? Or what if something great has passed me by and I didn't know it. I know these are big questions for such a "little" girl to be asking, but what if I don't ask them and it's too late to ask them. I hope that one day I will have answers to many of my life questions, but until then I guess all I can do is keep on going and never turn back.