Is it normal to think like this?

Is it normal to look at your life and say WOW i cant believe im here doing this and Im alone?Is it normal that many of my friends now have kids and are in different countries?Is it normal to be confused every day and have random bursts of sadness?Is it normal to be just twenty years old and cant belive that two years ago I had everything and felt so loved and secure and now I have to move on an leave it all behind .Is this normal? Is it normal that people change and your old friends become strangers and that you constantly feel lost on a journey to God knows where and to feel like a needle in a haystack.A very very lonely scared needle.