I forgot to say, your main issue is your squads are all over the place. Yea they all have the separatist tag but they don't synergize as well as they can. This website shows you common squads you'll see: https://swgohcounters.com/
Your IG-100 is getting wrecked because you don't have a character to dish out a lot of damage. Your squad is all about control without healing. That's a losing battle in GW. GW is all about attrition. I personally think you should start farming for Jango Fett. He has the separatist tag and he hits like a truck. His hard node farm also gives you HT, a good ship.
Here are the squads you do have and what you can do to fix them: General Grievious, IG-100, B2 (run this with 2 other droids instead)
4 Genonosians without GBA are pointless (get GBA)
Low gear/star ewoks (I wouldnt bother with them anymore for a while)
Run these Jedi: Bastila, Jolee, GMY, JKA, Ahsoka Tano