I'm sorry for your concern. Is your girlfriend having her Mirena removed? It's not for everyone. Her doctor may be able to help her find a different type of birth control that won't cause such a detriment to your sex life (and hers!). You're a good boyfriend to advocate for her health, and to raise concern when you saw a problem in your relationship. Men can learn from you in that regard. Good luck to both of you. Let us know how you are doing.