Raising 3x in the first place is also a mistake. With a 30bb stack, you should be raising 2.5x at most. Usually just a 2x should be fine(I rarely raise 2.5x and almost never do 3x because the effective stacks are rarely deep enough for it).
If you are opening 3x as a standard regardless of the stage of the tourney or stack size you are going to lose chips fast in certain situations such as this one, because you are opening for 10% of your stack with a weak hand and not only that you can't fold when you have to call another 10% more from a small 3b which is more often than not a monster(because they don't want you to fold so they don't raise as big, reverse psychology.
Randomly putting people on AK / AQ just because you don't want to believe they have a monster is a big mistake and will cost you time and time again if you don't stop doing that. This is the trademark big leak of a stubborn player who doesn't like to fold to 3bet because they don't want to give the 3b credit and want to try and outplay him or whatever post flop and then hit a pair and get stacked.
And as someone pointed out above, if your read was that he missed the flop, reraise shoving him is a bad play considering that in the case that he did have a hand(like here) he would call, but he fold all his trash/missed hands meaning you don't get any more value. Whereas if you just called, he might fire another barrel with the said trash/air hands. Your read was that he was trying to screw with you right? So let him go ahead and do it. As played though, while you might be able to get away from the hand post flop at times, I think this is one of the flops where your hand should be best often enough so I feel calling is fine.
Another thing I want to point out is that he is 3betting your 3x open. People generally don't want to mess around too much against 3x open(thats 10% of your effective stacks, if he want to 3b you standard 2.5x your open, he would be committed). Well actually 32k is not even a min raise here, min raise would be 24k to call since you raised 24 to the starting 12, but yes still slightly smaller than a 'standard' 3b but that might just be because you opened a 3x making it all weird with the effective stacks.
The main mistakes here imo are
1. opening 3x
2. calling the 3b
could possibly be linked back to the 3x open, giving you better
odds to call)
3. assuming opponent has AK/AQ
if he is 3betting you for value sure maybe they make up like near half of his range but you can't just assume he HAS to have those hands.
if he has been 3betting your steals light then his range is surely wider
4. reraise shoving on the flop