Is it bad to be an Introvert?

I am an Introvert with anxiety and depression living in NYC. When I am going to work or just out in general I really don't interact with people.I just keep to myself. I blast my music, walk with my head down and just stay in my own little world. If someone tries to talk to me, I will engage in conversation. Over the years I've become a bit cold and care less about life. I use to be this nice and caring guy that tried to please everyone and make everyone happy.But after being screwed over and over again by friends and people around me I just became cold. I wasted so many years helping others that I forgot to take care of myself. I am 29 and just wasted all my talent and potential. I've decided to just focus on myself and pick and choose the right people to do good things for. I now have a small circle of friends and hope to keep it that way. After all 4 quarters is better than 100 pennies. As for relationships, and don't care much to find love anymore. Don't even know if I want to get married any more.