Sorry for your current scenarios, friend.
Once again I see commonalities between us. My holidays (Thanksgiving, Christmas, and New Year's) haven't been the same either, ironically since 2011. In January of that year I was suddenly downsized from my beloved job. This loss of work was the reason for the end of my marriage, the negative change of the concept of "family," me experiencing complete abandonment (by my ex-wife, her family, and mine)--I know how Christ felt in the Garden when the apostles split, and my greatest recovery/victory thanks to God.
Since 2013 I have been alone on T-day, Christmas, and NY's Eve. I tell others that I am spending the day with an aunt--who is fictional. I have gotten used to these solo events, though these year I was a bit depressed about Thanksgiving prior to the day. It eventually went away.
I was closer to my maternal side, both in terms of relations and geography. We were all close, visiting each other throughout the 70's to the 90's. Since the kids (first cousins) became the adults and our parents passed away, it was also Exit Stage Left. My three cousins, especially the one I was closest to, blew the exit door off the hinges in 2011 and 2012, lol.
My ex and I also had no kids. I too suffer from depression, have been my worst enemy, and know the sting of wanting things which ended/never happened and feeling that they weren't meant for me. Since I was younger I have felt that me having a good woman/wife/relationship wasn't meant for me. In my 20s I used to see a couple in the street looking lovey-dovey maybe holding hands, or an attractive girl and I used to say to myself "that's not meant for me."
Try not to be so hard on yourself. I am a former expert on this. As a Christian, you know we strive to be Christ-like but can never truly be error-free like He is. In this fallen world, there is no 100%--none that I can think. We fall trying to be like Him, so it is natural we will fall in other endeavors. Just dust yourself off and get back on the road. Most of all, let your weakness be your source for Divine strength. Lean on Him and pray for strength and support.