The affair wasn't the worst part. The worst part was discovering how thoroughly he had been lied to for two years while building a life with someone. After that, trust felt like a luxury other people could afford.
He functioned. He dated, briefly, badly. He kept friends at the distance where they couldn't hurt him. He didn't call it depression because he was still going to work.
Coaching didn't make him trust people. It made him notice the part of him that had stopped trusting himself first. Once that part was met, slowly, the rest started to follow.
Composite story. Details have been changed to protect identities and do not refer to any single individual.