Spell to become monogamous

Any spellwork or deity work that can make me be monogamous?

Since i was very little ive had polyamorous thoughts and behaviors. I think its a. Oble way of developing in a relationship while giving the other person liberty and trust.

Now im in a loving relationship with my gf but she is monogamous. Weve been monogamous for 8 months and weve had the talk and she doesnt want to do an open relationship. I want to be with her since she has been there in my lowest moments.