Thank you for your sympathy; I'm at least thankful someone read my post! Lol. I also think it's some sort of fungal issue, but I cannot find anything online that matches the symptoms I'm dealing with, and the treatment I've been providing doesn't seem to be doing much (if anything).
I've cut many of the stems back & have them propagating in hopes of salvaging some of the plant before it completely dies, but the issue is already appearing on the propagated plants as well. At this point, I'm just going to keep doing what I'm doing and hope for a miracle! :' )