Is waking up at night with emotional surges a sign of "anxiety"?

Sometimes I wake up in the middle of the night. Sometimes it happens just as I am about to fall asleep. I am suddenly overwhelmed by a surge of emotion, related to a single thought, and am overtaken with fear or sadness. For example, most commonly it "occurs" to me that my parents are elderly and I may lose them soon and this wave of sadness just overtakes me. I call it "hyper-reality" because it FEELS like it's 1000 times more "real", more RAW of an emotion than when I just think about it normally. Recently I left a relationship and while I work all day to "handle" it at night sometimes I wake up with the thought "Oh God, he is really gone" and a feeling of panic consumes me, I am completely, hysterically distraught. Usually the worse part only lasts until I am fully awake and then it slowly over time diminishes. I have to get out of bed and sosomething to make it fully go away. It's disrupting my sleep. Then I often feel depressed all day or even for days. What IS this?