Why does perfectionism make Metta stressful despite aiming for acceptance?

I am perfectionist and self-critical in nature and this completely fuels my anxiety. I attempt to reach perfection in my Metta, examining every word and feeling, a factor that leads to more stress. Is it even possible that directed Metta practices that aim at acceptance can be used to heal the psychological causes of this ancient habit of perfectionism, or does it have to be rigidly treated? My name is Sameer, born on 1st January 1993. Time: 8:15 PM. Location: Hyderabad.