"Burning Bridges" is a common phrase used to describe eliminating ties with someone. Despite the negative connotation behind it, I believe that it's perfectly healthy to cut people out of your life that are toxic and threaten your happiness.
Don't you dare listen to anyone who shames you for eliminating toxic people from your life. If you knew a rose had thorns and it pricked you everytime you tried to touch it, why would you keep trying to pick it up?
I've burned a few bridges in my time, but not for anyone who didn't deserve it or who didn't push me away first. I've tried to cross bridges that I should have burned long ago in an attempt to mend the connection with the person at the other end, but it only led to heartbreak and the realization that some people won't try to connect with you until you've lit the match.
Now, I'm not saying to burn every bridge you have, absolutely not. Many bridges are lined with gold and warmth, built with love and laughter. These bridges, the ones held up with deep conversations, understanding, and sincerity, are the ones meant to stand for years and even lifetimes. But the weak, decrepit bridges held up by nothing but empty promises are the ones that will catch fire the easiest. The person standing on the other side will have either walked away long ago or will run up to see the bridge lit aflame and seem shocked, like this could have never happened and that they could have never caused anything to lead to it. These same people will have been the ones who blamed you for things you didn't do and make you feel bad for not being there for them when they'd never been there for you. The things you'd trusted them with suddenly became ammunition, and that was when you'd decided to light the match.
Burning bridges is not a selfish act, and never let anyone tell you that you're selfish or overreacting by pushing out people who treat you less than what you know you are.