Help with D2:LOD

I'm running a level 79 Straight summoner druid. Grizzly is maxed, as are synergies. Working on Hurricane, but only level 6. Act 2 Holy Freeze Merc is with me I'm trying to do Hell countess and Andariel runs, but physical immunity is killing me. I'll post pics of gear, if needed, but I'm struggling. I've run like 20 Countess runs, but best rune I got was Shael- Sol. Maybe a Lem and a Lum. Any advice, trades (Have IK Helmet also) or gear idea is welcome!

Typically if your build only focuses on one element, then you skip all the monsters who you come across that are immune to it. Like a pure blizz sorc will simply skip any cold immunes.

However you can get a Wand with Decrepify or Amplify Damage charges which will break physical immunes if you really want to kill them.

You should also put a point into Werebear and Shock Wave and use that for crowd control.

You can always go back to NM and farm some meph/ pindle/ etc. No need to rush into hell under geared.

Like BillyMaysed said, if your build can't deal with physical immune you either skip them or find a source of Amplify Damage/ Decrepify.
Lawbringer on a hammer would allow you to bypass physical immunity on ghosts during Countess runs thanks to Sanctuary Aura (only for yourself, not for your summons) but I have no idea how well it works for a summon druid.

The Countess is the best farming place for mid-runes and Andariel is good for starting gear but I think the Pit would also be a good farming place for you. Odds for finding mid-runes/sets/uniques aren't as good, however it can drop any item in the game and the difficulty is manageable even with starting gear.