Now, here's the next secret to detachment. Detachment is NOT a betrayal of love, it is a prerequisite to having a strong vibrant loving relationship. Try to notice how you are actually able to be more supportive/compassionate/understanding to *both yourself and SO* through this as you continue to detach. For, when you don't have to make everything about yourself, which is truly what is going on in deeply enmeshed Rs, you become far less reactive and able to really hear your SO and hear yourself, and see the humanity in both of you, in any exchange.
So often I think folks fear that detachment means a betrayal of love and/or in many cases, people fear that if they detach they'll find they don't really love their P (if folks can be that honest with themselves...). But, in fact the opposite is true, detachment paves the way for love, for appreciating yourself and the other person for who they really.
Anyway, you are doing great, and if you pay attention to how detaching is really enriching your life and opening up the possibilities for good Rs, then it will become easier.