I think all relationships add flavor and purpose to our lives. They go through seasons, changing and growing all the time. Sometimes our relationships give us what we need and sometimes they do not. I don't think the answer is to discard relationships that do not seem to be beneficial in the moment. Sometimes you need to step away to gain perspective. When we react to a person and it does not feel pleasant, the answer is not to discard them permanently. In my experience, try to back up a few steps, outside the ring of emotion to gain insight. If a relationship is sucking the life out of you, briefly take the space you need to regain peace and to ground yourself.
I can think of a few relationships I struggled with but eventually found myself going back to to rebuild. Try hard to avoid lashing out when somebody makes the hair on the back of your neck stand up. Realize you are two different people with differing perspectives and thought processes. Back away to gain composure and insight. You will someday get back to growing the relationship in a positive manner, if they were meant to be in your life. Sometimes the not so comfortable relational situations, when played out without too much emotion, can bring you to a point inner growth that will be valuable throughout life.
This may now be clear as mud, but I hope not. The gist of what I am trying to say is this; if you cared enough to engage in a relationship with someone, they and it are not worthy of being cast aside. Take the time to let your relationships pass through the seasons of life. Try to avoid being too quick to remove those who were once important to you.