Beth,
First, have you talked to your doctor about this? You are taking a lot of drugs - so that could be the problem.
Second, there is a difference between not enjoying sex and not having orgasms. You are able to have orgasms- just with a sex toy. So what you need to do is to incorporate using that sex toy into having sex with your husband. Let him use the sex toy on you. Use the sex toys for awhile - then switch to without- and then back to the sex toy.
The fact you can orgasm with sex toy means you are capable of orgasm. But it sounds like what you need is more intense stimulation and direct stimulation that a sex toy provides.
Vaginal sex/missionary position is not really about orgasm - it is about making babies. A lot of women have difficulty having orgasms from vaginal sex. The stimulation a women receives from vaginal sex/mp just isn't enough or in the right places. So they have oral sex or other kinds of sex first - they are 99% of the way to orgasm-then they start having vaginal sex/mp with their partner and they they go the final 1%.
In addition to your health - you are just getting older. Women sexual needs change as they age because their bodies change. SO they have to change the way they have had sex. They can have just as good or better sex - just not the same way. SO try experimenting and changing positions. If you miss gspot orgasms especially- try sex doggie style/vaginal entry from behind.
Because of all the drugs you are taking and the fact you are getting older - you may also be getting dryer. You may need more lubrication than you have needed before. There are lots of lubrications on the market - but the best ones are sold in sex stores or online - not in the grocery store. Eros has a line of lubrication for women that soaks into the skin to help not only lubricate for sex- but make your vagina less dry all the time. I never tried this - but there silicone lubrication is my absolute favorite - so I am going to think that there women's formula is also good. You can get it from a link on this page.
Good luck. You don't have as big a problem as you think - since sex with a sex toy is good. You just need to experiment some more AND talk to your doctor.
Susan