Read this my lovely.
www.considerthismoment.com/reason-season-lifetime/
Some friends are here for a reason, some friends are here for a season. Most of the time, they are here when we need them, and sometimes go when we don't need them anymore. Like Nanny McPhee.
It can be tough when you have none though.
I have a mixture of stories of friends I had for a short while who I loved and who disappeared after a few months, who I still think about at least once a week, and who fill my head with lovely memories.
And then there are friends who are still around, who get on my nerves half the time, and who I dread seeing because they just moan.
Then there are a few friends whose company I enjoy and see every few weeks.
I also have 2 friends who I have known since childhood, who live 20 to 40 miles away, who I see only every 4 months, but I know we would be there for each other if we needed it.
Upshot is though that friends can be a blessing, and a curse, and I am sorry you are feeling this way. But I am sure someone will come into your life soon... 
Maybe try hobby groups? Local facebook groups,