At 70 I have had MS for 27 years. I live alone and find a struggle to get much done. I am ambulatory but with balance challenges so I stay home - going out can be a real burden but then I get depressed. Everyone suggests excercise but that makes it worse for me - It is hard to be social and feel crummy.
I would have suggested a paratransit service for assistance in getting out, but it sounds like that might be difficult. I guess it's a tradeoff between the value of human interaction vs. the physical challenges. But do be aware that paratransit functions of local transit agencies provide service with small van sized buses with accommodation for wheelchairs.
Music and art therapy are known as having therapeutic qualities. Perhaps you could start your day by listening to favorite music, spend some time at an MS forum, and do some drawing or coloring inbetween. Coloring books can be ordered online; I know of an excellent source if you need one.
With the recent development of the Zentangles and Entanglement style of drawing, there's a proliferation of coloring books, some of which are tolerable but most of which are challenges for the eyes. I've yet to see one which I would buy. But there are better coloring books available.
One thing I've done is create collages of flowers and foliage plants by clipping photos from gardening catalogues. I use stick glue to attach them to paper, then slide them into the many 3 ring binders I use for legal and financial projects. Every time I pick up the binder, my breath is literally taken away by the beautiful combination of flowers. And, they're instant "pick-me-ups".
I create something similiar for my father, gluing photos of WWII aircraft onto a cardboard box in which he stores items he needs close at hand. Every time he looks at a B-17, it's a reminder of his military service, of men he met, of experiences they shared, of the fascinating technology of aircraft. It's a diversion.
Are you getting Meals on Wheels? There's a bit of social interaction with the delivery people, nominal, but everything helps.
I'm wondering also if you do any needlework or if the MS affects your hands. If you can work even simple quilts, such as those that are tied, there are many organizations which have adopted this activity as their method of helping infants, people in nursing homes and of course veterans. The Quilts of Valor project is one.
Another option if you feel comfortable with this challenge is inviting people to your house, with a BYO policy. They bring the food, set up trays or set the table, and you can engage in discussions on topics of interest.
If you're a college graduate, the American Assn. of University Women might be a consideration. I went to a few of their Foreign Relations group meetings and found them to be a highly educated, knowledgeable, forward thinking and sophisticated group of women. It was enlightening to engage in their foreign policy discussions.
There also might be a type of shut-in daily call that a senior center has for people to contact others on phone lists. It would be an opportunity to help others while meeting new people via phones.
You could also contact local charities and see if there's any work you could do at home, again, something along the line of the home work that's returned to the charity when finished for distribution to needy recipients.
Another, perhaps longer term suggestion, is to inquire if you can get a therapy dog to assist you at home.