In terms of how far through the game you are:
You must be at least four-sevenths through to have reached that part. You might be as much as six-sevenths through.
In terms of experience, if you play the game 'normally' and do just about every side-quest there is, expect to end about Level 27/28. If you go out of your way to get Max XP, totally planning your game round it, you can reach 31 without any exploits.
In general the drexl larva hits hard, so ranged weapons are better than trying to whack it with a lightsaber. Force powers are best of all. Try using a stim that improves whatever attribute you are using to aim (STR for melee (unless you are using finesse), DEX for ranged).
And just before the battle, make sure your gloves, belt and implant are maximised for combat; no point having stuff that protects you from Force powers or energy or grenades or that increase your ability to defuse mines; the drexl isn't going to be doing you any damage but melee

Choose things that reduce melee damage or increase your attack or damage. If you're using a lightsaber, replace any blaster deflect crystals with ones that add to whatever damage you're doing.
And get a Jedi to heal you during the battle!