Very easy fold I'd say, you might be crushed by a set or still an underdog against a monsterdraw, and if he has J8 or JJ you are looking at reverse implieds.

yes, if you are folding this, you are waaaay overfolding. Anyway It would be nice to add SB-s 3 bet % and tendencies in 3 bet pots (for example there are guys who always cbet pot in 3bp) , its better to evaluate then. SB should not have too many JJ-s and 88 s in his range. J8 is possible though. He seems aggro to me, so without further reads, my plan would be to call turn, and get it in on 2,3,4,5,6,(7,)-iffy,K that are non diamonds. On any other card, fold to his barrel if he bets big. If diamond comes, and he checks than you might consider using your K blocker. (I personally would bet 1/3 pot there-it rarerly induces anything, u get to SD cheaply, you not getting bluffed on rivers, its deceptive when you hit your boat). If non diamond 9,T,Q,A comes and he ckeks, I'd check behind, and reevalueate if he bets river.

PS: he is not donkbetting, he is cbetting. (Donk is when you bet into the PFR OOP and do not let him bet first)

sorry the title misslead me to believe we were the 3bettor and facing a potsize donkbet... obv Im not folding against a range thats likely AA** when we have 2pair.

Thanks for the comments guys, really appreciate the time you take to answer - apologies about the misleading title - still learning.