Hi JADEN,
I'm typically just a lurker, but I've broken my silence so I figured I'd go all out, lol.
I don't know of your experience, I'm assuming you posted it in an earlier post but I was drawn to your feeling strong emotions and feeling intense sadness coming from them even though they look happy sounds like you have empathy.
I started having similar experiences when I was 16. I would notice when I got on a bus that as I passed people I would experience a wide array of emotions that I couldn't explain. And they didn't seem to fit the emotions the people where showing. One particular time I was feeling anger seething from this one, but she was just sitting there smiling and looking content. But then something happened and she stood up and flew into a rage as she was getting off the bus, it totally blew me away.
At first I thought I was losing my mind, but then when I explained it to my mom she told me about empathy. Once I realized what was going on, then I felt relieved that it had a name and then I worked on shielding myself from other's emotions and learning to let go of them if I did pick them up. I also don't go into big crowds very often as it is extremely exhausting.
It could be that your experience you referenced was the beginning of a new sensitivity that you were introduced to. Also, I did have some experiences when I was 17 of black figures being in my room that scared the living crap out of me. I felt like I was being watched. I don't see them anymore, but I don't know if it's because they aren't there or maybe I have a new way of sensing them? It happened closely around the time that my empathy started...so maybe they are related? Just pure speculation on my part. Hope this was helpful in some way