A predatory animal is much more likely to attack a one party group as apposed to 2+.

This is entirely true. But since you bring up predatory instinct, my observation is that self-preservation is a far more primary instinct and this works brilliantly in your favor.

First, predators prey on other animals in order to eat. It is how they make a living. They generally don't do it just for fun or out of some primal need to attack things constantly. It puts food in their belly. This makes them very pragmatic about how they do their job. Easy prey is what they want. The easier, the better. And once they have a full belly, they're happy just to sleep or play with the kids.

Second, predators don't have hospitals or veterinarians to patch them up if they get hurt. They just lick their wounds and hope for the best. This makes them inherently cautious about picking a fight for no reason at all. Lose an eye in a fight and you have put your whole survival at jeopardy. Why chance it for no good reason?

Third, you are a large predator in the eyes of most other predators. It takes one to know one, as they say. This disqualifies you as a normal food source. To the best of my knowledge, the only two predators who have a known history of eating people when given a clear chance at them are Asian tigers and arctic polar bears. We only appear on the menu for most other predators when they are truly desperate enough to try anything.

Lastly, being a large predator makes you dangerous to tangle with at any time. That's really why they are twice as loathe to attack a group of two compared to an individual. It is because we are dangerous to attack. You fear being wounded or killed in a fight with a big predator? That's sensible. But the animals share that exact same fear. This fortunate fact makes you both want to avoid one another. You are doubly in luck, because the keen senses all predators possess in order to find their prey also allows them to be extraordinarily good at finding you and avoiding you!

The situations where all these facts in your favor are overridden and a large predatory animal will choose to attack you are extremely rare, can be learned, and can mostly be avoided by the application of that knowledge and a bit of foresight. For example, if you see a fresh cougar kill, leave it at once, don't hang around to gawk and take photos. Following a handful of obvious rules like this one should go a long way toward keeping you safe from a bad encounter.

But what you are experiencing is fear based on your imagining being attacked. It isn't based on a memory of being attacked. And once this imagined scenario becomes deeply lodged in your brain, it is hard to dislodge. But it is a fantasy, not a memory.