I just had a total hysterectomy 7 weeks ago. Because I was thrown into surgical menopause my hormones went nuts (can't take HRT due to cancer diagnosis). Thankfully, my orgasmic ability hasn't been hindered but I have heard that some women do experience a decrease of desire as menopause goes along. Mind you, this isn't everyone. I think it's a good idea to get your blood pressure checked and let your gyn know about your difficulty reaching orgasm. They may take your hormone levels and find that they are low. It also could be as simple as varying your routine. Maybe your system needs to be "shocked" a bit. 
