Your marriage could last for many more years, so you absolutely MUST start communicating right now. Talking about sexual needs, likes/dislikes, desires, etc., is not to be done in the bedroom - that puts pressure on partners. Turn off the TV, and put down the books if necessary, but begin to talk about the thing that matters - your relationship. Start talking over meals, during the evenings, or even go out for a meal and chat. It's quite hard to fall asleep in a pub/restaurant, so that might work. The prospect of spending another half of a lifetime with someone and not actually communicating one's wants and needs is one I find scary.
Secondly, you are getting older but it isn't right that you are both so tired all the time. I think that visits to the GP with blood tests to check on thyroid levels, & potential Type 2 Diabetes, etc., would make a great deal of sense. You may have to change your 'lifestyle', but a life restricted by torpidity is not inevitable. I have injuries that restrict me in my choice of sexual positions, but submitting to being too tired to make a physical connection is rarely a good move.
You may have to change somewhat your perception of just what sex consists of as you age. It does not always have to be the orgasm-led PIV intercourse that many tend to have in their relative youth. You need to research this together as a project and discover lots of new avenues of sexuality. Try them all out: some will prove to be a dead loss, others will be quite appealing and deserve further investigation. I would urge you not to dismiss anything without looking into it. I cannot imagine any man not liking a blowjob of decent quality, so why not set yourself a target of becoming an BJ expert? If he isn't a talented lover of going down on you, then that could equally well be a goal of his. Giving a partner pleasure is my target in sex; my orgasm takes a back seat and my pleasure often comes directly from the place I take her to.
The menopause can be pretty tough for some women, but do try to regard it with a positive frame of mind. My wonderful partner looked at it from the point of view that it was a final release from the tyranny of periods. We already had no worries about pregnancy, having both been seen to in previous relationships. We are now a couple of years into post-menopause and it's marvelous.
This problem is not going to be solved by simply 'dressing up', or buying a vibrator. Things like that may be part of a solution brought about by a fundamental change in your communication about your sexuality, so get talking - now.
Best wishes.