Razzleberry, I hope you will go for marriage counseling even if your H won't accompany you. After about 12 years of marriage, I asked my H is he would go to marriage counseling but he didn't want to. I took that to mean that he thought our relationship was just fine the way it was and that we had no problems. I felt the marriage was slipping away from us, but I let his refusal to do counseling reassure me that things were fine. This was such a mistake. What I didn't know then, was that a person can work on a relationship on their own, with a counselor. I wish I had seen a marriage counselor alone even if he wouldn't come. But I just dropped it and sought no help. I had no desire to blame him. I just wanted to stop the marriage from sliding and save our relationship. I urge you not to give up! My marriage is ending in divorce, after over 20 years together. I wish I had tried harder back then and pushed him more to seek help with me. Or at least sought help on my own. Maybe I just gave up. Things did not get better on their own.
I hope you will seek counseling on your own with a family or marriage therapist to work on this issue. I wonder could your H be confused about the purpose of the visit to the nurse? Is it for advice on your behavior as relates to meds? Or is it couples counseling? He might also be reluctant to go to the nurse for couples counseling as you have a prior relationship with her. Maybe if you both started together with a family therapist that neither of you know, it would be easier for him. A lot of problems in marriages can be solved by better communication. Maybe if you suggested that the couples therapist would help with communication skills, it would seem less intimidating.
Good luck.