I Have Been Taking Premarin .625 Mg Since 1985, After

I have been taking Premarin .625 mg since 1985, after a partial hysterectomy. I had also suffered from severe migraines, but after getting adjusted to the Premarin, my migraines ceased. I am 74 years old and now my insurance will not pay for the Premarin. I had stayed on it primarily for the prevention of osteoporosis. I have never gone through symptoms of menopause. Because of my insurance, I switched to Estradoil 1 mg. a month ago. I have experienced nausea most days and in the last week, I am having severe pain in the pelvic area and worsened nausea. I had my urine checked to see if I had a UTI. I did not. I am divorced and have not had any sex in 3 years, so that ruled out in problems from that. Should I discontinue the Estradoil? If so, do I wean myself off of it or just stop it?