If you are anywhere near a ranking area, and you see corpses or body parts laying around, that probably means its occupied, even if you can't see the people actually ranking there (they may have left for a moment or are invisible). Look for mobs missing. The group could be invis to be resting, and to keep protection, so that if someone does show up, they can have the upper hand--which it sounds like they did. You shouldn't be going to any major ranking areas alone. There are a ton of elements in carrion fields that need to be taken into account to simply even be survivable. When you start needlessly overlooking these elements, bad things tend to happen.

The way I always view carrion fields is that it is medieval times, and only a few people have a banner that they fight for. The rest are just mercenaries looking to get the kill. Obviously there's some good apples in the bunch, but they are fewer and farther between than the bad apples. Just keep your head up, and keep at it. We all run into rough moments like these, when EVERYTHING is lost, and we have to start from scratch.