My therapist says he made his decision and I need to respect that and let him go
If he saw what you were doing and saying then he felt your disrespect. Respect is a big deal for men and making them feel loved by their woman. You might have crossed a boundary with your H that is a deal-breaker. You need to get your issues resolved and try showing repsect thru your actions.
Your therapist is right don't pursue him. Learn what it means to "let go." Sorry you are here, learn from this experience to become a better person for yourself.
M22,H45,W45 S21/18D12 Retain faith that you will prevail in the end, regardless of the difficulties and at the same time confront the most brutal facts of your current reality, whatever they might be.