I've had long time friendships that have ended because we grew apart.
Also, remember friendships are created at a point in time, as a time goes on and we evolve, they no longer suit our energetics.
I found i was a giving,low self esteem person when i was younger. As i grew stronger, i lost some of my old friends i made when i was younger. They liked the fact that i wasn't a threat to them. As soon as i wised up to a lot of stuff, they shut down and grew distant.
Everyone has a different adjenda. Most of the time, if you're feeling unappreciated by a friend, over and over, it's time to let them go and move on. What a friendship means to them could be different to you, or they lack the integrity to be honest and open with you.
This is what i found, more often then not. I would have friends be nice to me, but an unsettling feeling within lead me to believe more. As it turns out, these friendships weren't based on mutual respect and growth, but more on gaining energy thru control dramas & passive aggression.
You want someone who is honest, open, and genuinley cares about you and listens. If you feel they're using you, and you feel drained after being around them, thats a good sign it's not working.