Go to any stim vendor and buy the Rakghoul Vaccine for 2,000 credits. Or if you don't want to spend the money, you can do the dailies for the event on Tatooine.
You can earn the vaccine by finishing the dailies.
You do the "Tracking the Origin" quest? It's the one where you have to find the seperate 12 pieces of wreckage of the ship that crash landed on Tatooine.
Reroll on the Harbinger or The Fatman.
If you're in the East Coast and looking for a PvE server, I heard Canderous Ordo's good. If you're on the West, the Harbinger is the best choice.
You should do ALL the side quests, and heroics included.
Also, if you get killed by those droids, lure them out to the walkway and just align yourself and use overload to knock them down for instant kills.
Good luck.