How do I come to terms with a career that hardened me?

You gave years to work most people could not stand to look at. It changed you. That is not weakness; it is the cost of the job. First, let yourself say that plainly. You carried something heavy, and it left a mark. Whether it was worth it is the wrong question to get stuck on, because you cannot rerun those years. The better question is what you do with what you learned. You saw how people break and how they endure. Few understand that. That knowledge can still help others and yourself. Hardening kept you steady on the job. The job is ending now, and you can let some of it soften. Start small: one honest conversation, one thing you let yourself feel. You are not undoing the years. You are deciding they do not get the last word.