Yeah, keep in mind that we've all been living on this tiny little island with what amounts to less than 100 people. None of our characters are going to be extraordinarily worldly.
Yeah, you're in a sketchy spot, as is usual for an Evil character in a predominantly Good party. On the other hand, you're LE, so you won't be doing villainous-cackle for-the-lulzs evil stuff, and any decent group of murderhobos PCs will naturally generate large numbers of corpses.
That's not an alignment thing. That's a lazy character thing. A character needs to be multi-facated. I've already decided that Sacha loves children and won't sit aside while they're in danger, enjoys gourmet cheeses, and likes glass bottles.
Doing stuff for the Evulz is a waste of everyone's times.
Agreed on the latter point, but what you're talking about is the difference between CE and Stupid Evil. PCs can genuinely be well-played CE, but it takes a certain touch, and the vast majority of people who go the CE route
are lazy Stupid Evil sorts that just want to ape certain webcomic icons without understanding how the archetype works (or why it doesn't always work when playing with other people). Really well-played CE PCs don't even necessarily need to chronically backstab the party, they just need to be utterly horrifying at dramatically appropriate moments.
Ofc. nine times out of ten that results in the well-played CE being fragged or having to turn against the party anyways because, despite it being well-done OOC, none of their characters would tolerate that sort of behavior. So it only really works in Evil parties, which run into the usual problem of people not understanding how to play genuinely evil Evil instead of Stupid Evil, indulging in creepy fetishes, &c.
You probably could make a relatively petty sort of CE work within a party that wasn't otherwise all-Good, with something like prisoners mysteriously ending up dead after giving/refusing to give relevant information, random NPCs going missing from communities the party visits, sadistic tendencies in combat, &c. without pushing things over the edge.
Hell, the whole thing is sort of reminiscent of the old sheep-fucker joke, actually.
"See that city on the coast? I helped save that city from an army of goblins. They don't call me Petyr the Savior, though. And that ruined fortress in the mountains, I killed a lich there. Nor do they call me Petyr Lichbane. But you burn down one damned orphanage..."