Sadalgia

noun: A term used for feeling the two emotions, "sadness" and, "nostalgia" at the same time.
sad-al-juh
related forms
Sadalgic-adjective
Sadalgically-adverb
origin 2007 A.D.- Within the shadowy confines of my brain.

One could say, "I'm feeling a sudden outburst of Sadalgia".
Or, "Your prescence makes me Sadalgic".
It is recommended that the term be used under the pretense that you can actually feel these two emotions simultaneously.