Is it normal i feel awkward/nervous in public?

It's got to be you. People in general just don't care about strangers they don't even come in contact with enough to judge them or put them down.
It's all in your mind.
That being said, it doesn't make your feelings any more unreal. Just try to remember that most folks don't care two shits about strangers and what you think you see in their casual glances are probably just vacant stares right past you.

I used to feel like you do in my youth. As I got older I forced myself to mingle with others in various public and social settings until I could do it without thinking about it. Part of my transformation included initiating conversations with total strangers instead of waiting for them to speak to me first. In the process I discovered that many people were awkward and uncomfortable like I had been, and like I still was a little bit. By me talking to them I was helping them to fit in better and feel more normal and accepted. It made me feel good to realize that I had that power over other people and that I was able to help them to not feel so ill at ease.

My social transformation was pretty much completed the summer of 1999 when I was between jobs and had much of the summer off of work and spent a couple weeks (one day at a time) at the nude beach. Being totally naked and surrounded by naked people was somehow very liberating to me. It helped me to see how much we are all equal.

Perhaps you should force yourself to hold your head up and look at others. Don't stare and make them uncomfortable, so they feel threatened, but just look long enough to see that many of them feel like you feel now; insecure, inferior. You have the power by taking control of your feelings and the situation to help them feel better about themselves. You'll be doing them a favor and you'll be performing a "public service". People who like themselves and feel good about themselves are less of a threat to society, to the people around them.