Most people are terribly lonely. Even those who seem to have lots of friends.
Here are a few ideas to help:
1. Find friendship and fullness in Jesus. Then when you approach other friendships you will not be "needy".
2. Learn the art of self-disclosure. Many of us are imprisoned in loneliness because we won't let ourselves out to be seen, known, loved, cared for etc. We are afraid of revealing ourselves or we just don't know how.
3. Appreciate the relationships you have. Each friendship is at different levels at different times. Rather than longing for more, be thankful for what you have.
4. Be nice.
I know the last one might seem condescending or trite. But I genuinely work on this myself. It really does make a difference!