Six trolls raiding your home at once seems nearly impossible unless you used mods to make the game harder.

You usually get two trolls in a raid. You need to get out, kite them away and stick them with arrows. Usually the timer will run out before you killed one. Which is important, because every enemy you kill during the raid will spawn right back.

Kill them after the event expired.

Once you know the mechanics, the game becomes much easier. Especially the Elder. You fight it from behind the pillars that corner its altar. When it sends roots, you move to the next pillar, where you will be sufficiently safe from its flying tendrils. Just kite it around its altar.

During the whole time you pepper it with fire arrows.

Use lvl 3 Troll armor and a lvl 3 finewood bow. Eat deer stew and carrot soup. The third meal can be either deer for more health, boar jerky for a good mix of both health and stamina or just honey for stamina only.

Should be not too hard this way.

I can relate to your experience, though. Fighting the Elder the first time was a disaster for me as well. Now I know better.

Edit: 3 star trolls should not appear at the usual bronze age level. You probably used a mod to make that appear.