Niv,
I am so glad you wrote. Maybe this will help you. In my Christian faith, we learn how to love everyone as we love ourselves. This doesn't equal saying yes to everyone for their approval but learning how to live a balanced life. I have also learned that not every friendly person is my friend, not all friends will be in your life for forever. Some people are only in your life for a season but everyone is in your life for a reason.
We learn so many life lessons through our interactions with others. We learn how to love, forgive, the value of saying yes and no, time management, what is really important and so many other things.
One of the things I love about God is how he made each of us. He gave us a heart to love others but he was wise enough to put that vulnerable, strong yet fragile organ in our chest behind our rib cage protected from most hurt or harm that could come to it. We can learn so much from that by keeping our hearts protected.
Sometimes our hurt feelings don't come from the other person intentionally hurting us but because we tend to take everything so incredibly personal. Everything isn't personal. That "friend" didn't rush us off the phone or didn't speak to us out of malice but because they were just consumed by their own life struggles.
As a Christian, God is teaching me how to love myself better and as an extension of my relationship with God and myself the quality of my relationship with others is changing and becoming richer and more fulfulling but God is always my best friend and there for me and someone I can always talk to about everything from small to large and in between.