I spent the entire day with my best friend and felt sad and sick to my stomach when she had to go
Why did you feel sad and sick when she had to go?
Because I missed her terribly. I don't have nice conversations with anyone else.
You might want to make some more friends or acquaintances. You should not obsess over this one friend that you have. Doing so will only leave you unhappy.
Maybe you are right, but this is what I have right now and I it's terrible.
I'm sorry you're in such a bad situation right now. I really think that making more friends will be great for you, though, so you have more people that you can do fun things with.