Before I replace the counter I would repair the area as much as possible and install the sink with some sort of bracing or pressure applied from beneath the sink to support the sink from below
19'Duramax w/hips,12'Open Range,Titan Disc Brake
BD3,RV safepower,22" Blackstone
Ox Bedsaver,RV760 w/BC20,Glow Steps, Enduraplas25,Pedego
BakFlip,RVLock,5500 Onan LP,Prog.50A surge,Hughes autoformer
Porta Bote 8.0 Nissan,Sailun S637
Correct Trax,Splendide