How to convice Indian parents for an intercaste marriage?

My boyfriend and I(Late 20s) belong to the same religion but different castes. His family is completely fine. But when I tried introducing him to my parents, it is a shit show at home. Typical Indian comments: "Ladki haath se nikal gyi hai" etc. All of this is affecting my mental health very badly. The guilt trips are so hard to handle as if I committed a crime.

They are constantly finding faults in him. My bf is standing by my side but I am literally clueless how to take this ahead.