Log trolls do AOE damage, the same as if you use a stagbreaker, but bigger. This is why you can't plant your carrots too close to the edge of your defenses.

Those black forest stone towers are traps. They can be damaged by trolls, and more slowly by everything else, and you are not at a level where you can repair them yet. They're also pretty cramped inside even if you find a good one.

I've been experimenting with troll traps recently. Dig a ditch, place some beams across it. You can run across but the troll has to go the long way around. It takes some preparation, but I'm less likely to get splatted while getting hung up on things in the black forest. My last ditch wasn't long enough to handle both the troll and the greys that joined in. Die and learn. My philosophy is that there's no such thing as cheese when playing permadeath. It's just common sense to reduce risk as much as possible. Getting at least one piece of troll armor helps a lot before going into a crypt.

I'm having fun with permadeath runs. Partly it's because I like Valheim, and there don't seem to be any good substitutes out at the moment. So far, the furthest I've gotten was to be killed by the Elder after scouting the swamps. Got tangled up in the tendrils and couldn't move.