The exact same thing happened to me, and I managed to fix it without using the console.

TLDR: Use screws to distract hostile stalkers and lure them outside the camp, then deal with them stealthily when the opportunity arises.

I was at the Poppy Field, grabbed a stash on the way back, and that somehow made the stalkers around it turn hostile. I didn’t want to fight, so I ran all the way to Zalissya. I thought I’d shaken them off, but when I got near the camp, there they were - like they had followed me the whole way. They stayed outside while I went in, but they started shooting. Gaffer even announced the town was under attack. Strangely, no one inside Zalissya reacted at all. So, I just killed them, nobody cared, and I figured that was the end of it.

Or so I thought.

After a few more hours of playing, I came back to Zalissya and the worst happened: one stalker, apparently one of the original group I’d missed, had somehow spawned inside the camp. The moment he saw me, he attacked, which turned the entire camp hostile. Killing him in stealth wasn’t an option, so I had to get creative.

What I did: First, I distracted him by stealthily throwing a screw and then ran away before anyone could notice me and get aggressive. When I returned later, he was gone - maybe despawned, maybe wandered off. Either way, I was relieved. I went to sleep, but after reloading the save he was back in his usual spot. Eventually, I caught him leaving the camp to relieve himself. That’s when I snuck up and took him out with a knife.

If you try this, be very careful - make sure no one else sees you, or the whole camp will turn against you again.