I've tried replying but TWICE my long post does not get through, the "ball" just keeps twirling.
So I'll continue trying, but dividing my post to see if that will work.
Here goes the first section...

It's a heartbreaking experience when people whom you love(d) are no longer in your life. As human beings, we not only need but also crave the emotional and psychological support, particularly at our grayest moments. And the need for physical contact from embraces, holding hands, a kiss on the forehead/cheeks and yes, lips --- all are components of our humanity. I offer my empathy that you are in that situation that deprives you of this.

May I first of all suggest this: Focus on yourself, aim to release negative thoughts and feelings, allowing all of your energy toward self-healing. Negativity begets negativity. It's amazing how our emotional and psychological states impact on our physical being. I have suffered from clinical depression for nearly my entire life (in mid seventies now) and I am all too familiar with the grip that it can have on my daily wellbeing. Chronic, often very intense, physical pain is also my daily companion, and I feel worse on days that the guards for my mental wellbeing are lowest. I turn on the radio to what our adult children call The Old Fogey Station, and listen to both present and "old time" ballads. Or I’ll play CDs of oldies music, bringing me back to my pre-teen years and onward. Music has been shown to release endorphins, the "feel good" juices in the brain, and I savor the oftentimes warm, nostalgic memories that the music generates. So does exercise release endorphins, so do whatever (even limited) movements you can handle. MUSIC PLAYING WHILE I AM IN THE KITCHEN has made me break into dance moves from my younger years, making my body move to The Locomotion, The Twist, The Pony, etc., as well as some of the moves from when I used to lead dance-exercise and middle eastern dance classes for young girls. Needless to say, the body does not do what it used to do so effortlessly, but the point is that YES, I move and benefit from doing so.😁. It's uplifting, even if my moves have had to be "changed" a bit to accommodate my present body☺️.
ANOTHER IMPORTANT ASPECT: Engaging in even mild physical activity, even those done in-chair. There are TV programs in really early morning hours (5 to 6:30 am), even yoga and meditation. My insurance provides free membership in a program titled Silver Sneakers, with ability to go to an actual gym (designated), and also online Zoom classes of all kinds of physical programs. Sometimes there are hands-on activities, like learning skills and artistic offerings as well. All FREE. When possible, I’ll step outside (we are fortunate to own a home situated in a quiet, nature-enriched area of our town), and do walking on our ample sized deck, deep breathing and enjoying the rustle of the tree leaves, the sway of the tall trees that seem to brush the puffy clouds and blue sky. I can’t ambulate around the property due to ground areas being slightly uneven in places, thus presenting a danger to my unsteady, unbalanced gait. I’ll lean against the back rails of the deck, close my eyes and listen to the sounds of nature, absorbing he benefits of the sun. Get outside as often as you can; it’s refreshing and so beneficial. I used to do fast-walking at the town track but that had to be curtailed several years ago.
EXPLORE ARTISTIC OUTLETS. Hobby stores like Michael's offer FREE crafts classes and also art such as water painting, acrylic, charcoal, etc. Libraries have bulletin boards with posted info on activities especially meant for senior residents, and even prose and poetry writing. Lots of great things on youtube also! Help your brain form dendritic connections!

ATTEND A LOCAL SENIOR GROUP: Since you live alone, and alone due to familial circumstances, perhaps you could consider such a group (our town has one that meets regularly, for members to be socially involved via activities, invited speakers, or sharing tea/coffee/hot chocolate and baked goods, some which are made and brought in by members). They also arrange "field trips" to local places of interest. Our town offers free transport to the Senior Center, and there's a Lunch delivery program also. Do as little or as much as you wish. Social interaction will help with your loneliness and depression.

(more to come)