Destined to be alone?
I've always struggled to maintain friendships and romantic relationships. It's never been easy for me to relate to people or to bond with them, and if I do it never seems to last more than a handful of years before they leave and never talk to me again. I've tried changing myself so many times and it never seems to help. I'm beginning to wonder if fate just wants me to be alone for the rest of my life.
it just takes time to find the right balance you can't rush relationships whcih i am sure you know that by now friendships take time to devlop as well best of luck to you 
I don't think you're destined to be alone.
It's possible that those friendships are still there, more than you think. Do the people move away? Because that's an external factor that you can't get mad at yourself over. If they do keep moving away, then maybe your environment just sucks for building up real friendships. A lot of cities are like this.
What are you doing to help yourself make friends? What do you do to show interest and pursue the relationships?
There are some books that could help you.
We shape our own destinies.