First there is the question of whether you are a "conditioned mono" or a "natural mono".
If you're a conditioned mono, then perhaps you could be free to explore multiple loves yourself and enjoy more intimate people in your life.
As a natural mono, my benefits are solely hinged on the opportunity to love Redpepper. If she wasn't polyamorous I wouldn't be able to share her intimate love. In knowing she has a loving husband I am somewhat free to take time for myself that I might feel guilt over if it was just me and her.
I could still be involved in her family if we weren't intimately in love and all the aspects I have learned from poly could be applied in a mono relationship. It has brought out growth in me and realizations I might not otherwise been pushed to however.
It's good you are seeking help. Hopefully your therapist is relationship style neutral. I don't like the idea of anyone going to see a traditional relationship or poly friendly relationship therapist because both may have a tendency to preach their own beliefs whether intentional or not.
Take care and good luck in your journey