I'm sure the therapist did say something like "think about forgiveness towards Taylor" and he, being delusional, interpreted it as "I need to write my feelings in a song and send it to her so she can finally understand why she caused me pain, and only then, if she responds positively, I'll forgive her."

Any person practiced in forgiveness knows the act doesn't involve the other person at all, and isn't conditionally based on them doing anything.

It is a choice you make internally within yourself, by accepting they have hurt you and choosing not to hold on to the negative feeling of resentment.

Viola Davis is often quoted as saying, "forgiveness is giving up hope that the past could've been different."