I Am An Infj...now What?

I found out I was an INFJ five years ago, and the more I learn about myself (and confirm how INFJ-y I really am), the harder I find it to challenge the limitations of my personality type.  INFJ's tend to be perfectionists, and this is true for me especially.  I am struggling to be happy in relationships, and I find my tendency to withdraw is killing them.  So, I need help/advice.