If I sacrifice my unit with Deathgrip targeting a 2 might unit and the 2 might unit gets gusted, does my sacrificed unit still die?

Yes, your sacrificed unit will still die.

This interaction is governed by the principles of targeting and partial resolution (as seen in RiftJudge FAQ #10055 and #10226). Here is the sequence of events:

1. Playing Deathgrip: You play Deathgrip, targeting a friendly unit to kill (sacrifice) and another friendly unit to receive the Might bonus. When Deathgrip is placed on the chain, both units are locked as targets.
2. Playing Gust: Your opponent responds by playing Gust, targeting the unit you chose to receive the Might bonus. Gust is placed on top of the chain.
3. Chain Resolves (LIFO - Last-In, First-Out):
   • Resolution of Gust: Gust resolves first, returning your targeted unit to your hand.
   • Resolution of Deathgrip: Deathgrip now attempts to resolve.
     • Partial Resolution: While the unit intended to receive the Might bonus is no longer on the board and thus is an illegal target, the unit you targeted to be killed remains on the board and is still a legal target. Therefore, the spell resolves partially: you must still kill the friendly unit you targeted.
     • Might Bonus: Because the unit targeted to receive the Might bonus is no longer on the battlefield, the bonus cannot be applied.
     • Draw: You still draw one card, as the draw instruction is not contingent on the success of the other effects.

Summary: Because the target for the kill remains valid, the spell resolves partially and your unit is killed as instructed. You do not get the Might bonus, but you do still draw your card.