Struggling With Firing or Having Serious Discussions with Underperforming Employees

I am struggling to have difficult conversations with underperforming employees at work. I feel bad being direct with them because I don’t want them to feel badly about themselves but do want them to have clear expectations. I am trying to figure out what the block is to having these discussions even when I have a performance improvement plan ready to go for employees, I just need to schedule the talk and avoid scheduling. My question is, how do I figure out what is going on within me that I haven’t healed from that is causing me to have such strong avoidance behavior to employee performance discussions? There are a few people I need to fire, I have listened to Brooke’s podcast episode about “How to Fire People” and loved it! I recently (this Tuesday) used this method to fire someone and was completely crucified by the person I fired, it hurt and I am working to narrow down why I am so hurt by the words this person used to berate me. I just want to get to the bottom of what I am feeling and why when it comes to firing people or having difficult discussions with team members. I know it’s something inside me, and I am having trouble asking myself the right questions to tease it out and do the work on it. If you have any suggestions on how I can work through this or questions I should ask myself? I am doing a coaching call next week but thought I would try to prepare in advance for it by diving in a little deeper. Thank you so much in advance for your help!!