How should we react when Villians 3bet us overly small at different stack depths.

I just started grinding MTTs regularly after having a good series this summer.
Anyway I feel kinda awkward when 3bet small, I was over folding At first, typically assuming Villian had really nutty hands when they did this.

But if we open like (2x-2.25x) and get 3b to (4.5-4.75x) should we be defending almost all of our playable hands because of the odds we are getting?

The specific hand that came up recently to make me curious what we can be doing was,[230$ live donkament]

Hero <23~bb> opens A4s utg+2 (2bb) CO<28~bb>3b us to 4.5bb
I feel so awkward when i get put in spots like this preflop.
I think with this specific hand I can't fold given the odds. But what kind of range can we defend here? Almost anything I'm opening in early position?