АК after squeeze vs 4B =>5B =>cold call

Poker Stars, $0.02/$0.05 No Limit Hold'em Cash, 6 Players
Poker Tools Powered By Holdem Manager - The Ultimate Poker Software Suite.

Hero (SB): $5 (100 bb)
BB: $5.44 (108.8 bb)
UTG: $1.80 (36 bb)
MP: $6.90 (138 bb)
CO: $2.94 (58.8 bb)
BTN: $12.68 (253.6 bb)

Preflop: Hero is SB with A♥: K♠:
UTG calls $0.05, MP folds, CO raises to $0.25, BTN calls $0.25, Hero raises to $1.05, BB folds, UTG raises to $1.80 and is all-in, CO raises to $2.94 and is all-in, BTN calls $2.69, Hero ???

MP = 99/25 , 3b= 67, total hands 8
CO = 65/19 , 3b = 8 , total hands 33
BU = 32/21 , 3b= 5, total hands 78

So, after my squeeze and 5B shove from middle stack and cold call from BU that is not I wanted to see when squeezed (original limper 4b shove - that is how the fishes plays QQ+,AK) - the problem I got here is BU, he cold called. The original idea was to push vs short stack and push out middle stack from the hand. Also, isoraiser 5Bets - that means he has quite strong range, JJ+,AQ+. So, I lost few outs and now I got only 4-4,5 outs. The biggest problem here is BU. He covers me, I can't just call and after missing the flop fold. So, the desicions here are 1) push 2) fold. What are you commonly do in such spots? Thanks.