How have you worked on dealing with conflict? I have recently come to the realization that for the last 3 years, I have hated various jobs I have taken because I have failed to deal with conflict with specific co-workers. It has impacted my mindset so much that I have let it impact my performance as well and I have been ok being an average performer if I meant reducing interactions with certain people on high visibility projects. This is a problem and I want to fix it. Any recommendations?

Mel Robbins has great podcasts on building confidence.

Establish a rapport with folks, find common interests and build relationships. If that doesnt work and the person is unreasonable and wont meet you halfway, maybe time to move on. I also prepare myself with canned responses to negative feedback. It helps with my confidence level. How you react to it is key! Keep working on yourself. How to win friends and influence people is a wonderful read

A book “crucial conversations” would be good in this situation.

You are not alone with this.

Read “Critical Accountability” and “Set Boundaries, Find Peace”

Conflicts are part of life. I faced a similar situation right out of school.
I focused on learning about the different generations and personalities, and how they interact with each other at workplace.
I also focused on becoming more self aware, figured out what my default behavior was. For example, when I didn’t get along with a coworker, I didn’t address the issue and interacted with her only if I had to. Now I try to build relationships and address any disagreements in a 1:1 setting so that we are on the same page. I still have a hard time being confrontational, but I try my best to address the issues.
How you address the problem or what words you use also matter. I have my manager that I relied on for mentorship and coaching. I would suggest you to find a mentor who will guide you through these challenges.
Since you have mentioned that you have faced similar challenges with coworkers in multiple companies, I would recommend that you work on self awareness. Identify what type of work setting you thrive in, what are your default behaviors and answers, your reactions, etc.
I hope this helps. Good luck!

Work is like high school. Wherever you go to work, there will be clicks and people you don’t get along with. You weren’t hired to be “social”. You were hired to do a job. That being said, you still have to have a relationship with the people you work with. When you don’t like someone, keep it to yourself, and vent at home. Build a business relationship with those you don’t like. It’s transactional. Kill them with professionalism to get the job done. Sometimes the fun in not liking someone is in outshining them on the high road. If you can work through someone else without out it being an issue, great. But if you have to be in contact with them, be polite and professional.

All in all, you have to make a choice. For me, I look for other avenues to get work done if it is quite bad. In one relationship, I always ensure at least one other person is in the room with me when dealing with that one thorn in my side that I don’t get along with as they are a pure snake in the grass. But I stay professional. If there are several there that you really don’t like, ask yourself 2 questions. (1) How am I contributing to the issue? (2)If it isn’t going to change and I’m not happy, why am I staying? If you need to, change departments or companies.