I say this out the greatest concern, and not in any attempt to dismiss you:
I think the only help you will get is from Dr Harley himself. Ideally, both you and your husband would contact him, and you would be brutally honest about the things you have told us here, and you would say them in front of your husband.
A major part of your problem has been that you have always refused to discuss your unhappiness with your husband. You have often come here, asking what you can do to change yourself into someone that is happy, when it is clear to me, and to others that have written to you, that there is a fundamental problem in your lifestyle. Nobody can change themselves into a happy person if they hate the life they are living.
If you are clinically depressed, which you are beginning to sound as if you are, you need a rigorous clinical intervention to regulate and elevate your mood. However, even with that, you won't be actually happy if you continue to live the way you have been. If I remember correctly, you live on a farm somewhere isolated, which you hate. For some time you homeschooled some of your children, which you hated doing, and which isolated you further from the social interaction you craved. Your husband's work took up a lot of his time and emotional energy, leaving you feeling lonely. Now you say that his work, and all other activities have ceased, and you are together 24/7 - in your boredom, as it sounds to me.
Dr Harley has never said that spending 24 hours a day with your spouse will make you happy, and neither have we on this forum. We've tried to explore with you ways of making your time together more enjoyable, but you reject what we have said. You've come here today with an air of: "okay, you people. You claim to have all the answers, so fix this" - but I would say that we've tried. You seem (to me) to have an extreme set of circumstances which only an expert can help with. Your GP would be one place to start to try and access this expertise, and also, so would Dr Harley. He'll give you his time for free.
If you really want things to change, though, you'll need to stop faking it for your husband and let him know how deeply unhappy and unfulfilled you have been for so many years. The poor man can't do his part in changing your marriage if he doesn't even know anything is wrong.