Juggling with selfishness

What I regret most is that I've pushed others away and chosen to be selfish. It is healthy to put up boundaries between myself and others, but at the same time we are a unity of souls. I tried to retract from this. This paradox of the tension between healthy boundaries and healthy unity puzzles me. What is my place? Am I conscious of the world, am I humble? It feels as if I'm juggling with this in relationships and when I think of world news e.g. on poverty.
How can I be with boundaries and less selfish, open to the world at the same time?