Please don't give up. You have been through tremendous loss. Be kind to yourself. Promise yourself one small indulgence per day. At least you will have that to look forward to. I know the loneliness you feel is debilitating. I am lonely too. I will never have grandchildren. I sometimes wonder, why am I still here? But we are here! So we must live as best we can. You still have a life to live. Please don't give up! I hope this helps a little bit. You are not alone.

"am still so lonely" ...Oh the new pandemic that seems so perplexing because we are steps away from the other fellow humans, who, often are in the same pursuit that we are. This is what has occupied myself figuring out for the last about five years -- and getting more intense by the day. Just today I am going thru a government website about seniors living isolated and feeling lonely and another article in a national paper (Yes, I've pretty much gone thru every article on this subject in the New York Times and stored in my word files to look up and add personal notes) and I'll be calling or writing for more info in the hope that I'll find my little 'tribe' who enjoy meeting Each Other. Friendship is Mutual and therefore more honest -- and therefore rewarding -- than a spouse or sibling.

Now since we live in a ever changing society, I believe we should invent 'Spontaneous Friendships' where we Enjoy each other for whatever time we have together, whether one week or a few years. After all LIFE comes with No Guarantees. Why not plan our lives with the current restraints. To expect otherwise is to invite upon ourselves just because we dared not look at our actual circumstances.
Here's the good news for you: Women are much more open to forming friendships than men, who are too uptight about forming male friendships. I, frankly, find it bizarre that what Aristotle considered so important that he said: Life without a friend is not worth living. I am starving to find a fellow human man or woman, young or old, poor or well-off, to engage in exchanging ideas about, for example, why we've problem Talking about our Friendlessness. Or about a book, movie, ms. Swift's pull, even grade 10 school math or science. WHY it'd matter who you are except honest interest in a discussion.
Finally, I get up from restful sleep because if I did not do anything to find friends, how would I feel even a few weeks later? If I needed work, won't I'd go about finding it every day full throttle? In fact I've started on meetup.com and so far no luck -- older folks ain't here.
I've exhausted all programs in libraries within 30 min distance via public transport. But I know there is no other way but to keep on looking. I wish you get there before me! Good Luck