I'm a Zoologist/Ecologist with an interest in cryptozoology and I've been researching Fleshgaits for a few years now and I have an hypothesis;

Fleshgaits were...'Humanity's Natural Predator' as it were. 'Designed' (for lack of a better word) to keep the human race in check. To keep our numbers low. And for hundreds of thousands of years they did just that. But starting around the Industrial Revolution - and especially after WW2, we proliferated so quickly that we overwhelmed them. And by our expansion, they have suffered severely and are dieing off. This loss of elders and/or training, loss of habitat, and the internet-based sudden increase in our access to knowledge about Cryptids, has resulted in much fewer numbers, and the remaining ones aren't of the best Ilk.

Where once they were all-but unknown to us; able to blend in almost seamlessly - almost perfectly appearing human to get close to their prey (Us). Nothing more than the root of most, if not all, "Shapechanger" or "Humanoid" Myths: Werewolves, Skinwalkers (yee naaldlooshii), Wendigo, Vampires, Satyrs, Mermaids, etc. Even things like the more modern Internet phenomena like SlenderMan and The Rake could have their beginnings in Fleshgaits.

But, the remaining ones aren't as skilled in these abilities. No longer able to quite capture the look of humans - perhaps at a distance, but their natural appearance is...'Wrong'. Which may be what you saw. They can still imitate voices, but they can't quite get the look down.

There are many stories of these creatures meeting up with groups of campers and hikers, usually late evening/night or only in large groups, where someone only realizes something is wrong by little things - backpacks and clothing changing colors or appearing and disappearing, or just the wrong number of people, "Hey Bob, wasn't there 12 of us on this boyscout hike? Cause, including us, I'm counting 13 sitting roasting marshmallows around the campfire this evening."

The good news is; They're not really all that smart. By that I mean, I'm not sure if they're even Sapient, acting more on instinct than deep thought like humans do. They can be very crafty, so don't underestimate them, but they aren't as overall intelligent as we are. And, I don't believe their...'mind-effecting' ability is anything supernatural, it's more akin to how humans deal with the "Uncanny Valley" - your brain recognizes that something is wrong, but you can't rationalize what you're looking at. And, you used the correct term, they are Paranormal, but not Supernatural. There's nothing really beyond our understanding of Science - or at least what Science says is possible, they aren't "Magic" for instance. Even if they're what Werewolves are based on, you don't need Silver Bullets to kill one. For example.

As you mentioned the 'Fight or Flight Response', there's actually a third - 'Freeze'. When suddenly exposed to danger, we either Run, Strike, or Lock Up. Any of the 3 can be useful in its place - Not Moving is a good idea if the danger hasn't seen you yet...sometimes. Even with heightened olfactory and auditory abilities, most predators still rely on Sight to judge distance and movement (although Jurassic Park didn't quite get the T Rex' visual accuity down exactly 😄).

Now that you're aware of it, and you arm yourself with that knowledge - you can process through it (that's something humans excel at, that pehaps nothing else on Earth can do) and that Oppressive feeling won't weigh down on you if you encounter it again.

In fact, the very word and concept of 'Panic' may come from these things. The Panic in the Woods (often stylised as PANic in the Woods to emphasize the etymological root to the Greek god Pan - the personification of The Wild) is the name given to a mysterious force experienced by those far from civilization, such as hunters, campers, and hikers. Victims sense imminent danger, leading them to flee the area. Often running blindly into the woods and becoming lost. Survivors claim they felt at the time that they had to run, but upon regaining their sanity they were completely lost.

If you find yourself feeling that Oppressive otherworldly feeling out of nowhere again, fire your Glock! Which you should start carrying for the time being. The loud noise alone should startle you back to a semblance of normalcy. Plus, it'll remind you...and It...that you're not a weak, defenseless victim.

There are stories of Fleshgaits stalking individuals - so keep your senses sharp for a while. Especially if you live near, or often travel through, more rural areas. Same goes with your family - especially your daughter. It may consider her it's chosen prey. Talk to her (and her friend if it's not too awkward) about what happened. Get her (them) to be aware and forewarned about this thing. Make sure they avoid wild areas and pay extra careful attention to their surroundings.

All this, of course, is based on my assumption that this is, in fact, a fleshgait. If it's something else, then...uhh, I got nothin'!

Keep me In The Loop on this. As I said, I've been researching this for awhile now and would like access to any further info that comes up, please.

I mean, you happen to have styrofoam and gasoline? If so it’s napalm time, if you know their general area, burn the general area :).

Edit: looked into it and ash seems to keep them away, so since fire creates ash, fire is good against them

Look up 'Panic in the Woods Phenomenon '.

It's been reported since Ancient Greece or even further back.

It goes well beyond normal fear of being hunted. It's the Fear you talked about. Even from experienced hunters and soldiers armed with high-tech, military weapons. Rangers and Green Beret types have talked about sudden, pants-shitting fear just out of the blue, middle of a nice calm day, type situations.

The idea I'm touting is that the Greek God Pan - who Satyrs and even Satan/the Devil's appearance is based on - could have, itself, been based on a Fleshgait.

What if it has something to do with frequency and vibration? The way we see/hear/feel things is rooted in the way the particular thing vibrates, so maybe they’re less shapeshifting and more frequency-shifting creatures . . . Just a thought.