From what i gather from Shaurya and Arav's talk, i think Shaurya is protecting the Nanda's coz he knows that he wont be able to stop his mum and brother (and i think he hasnt a great relationship with them and doesnt want to be involved with them), getting what they want but Shaurya can definately protect the Nanda's with his care and kindness and be with them, if you get what i mean
I think Shaurya hestitated telling the Nanda family the truth about who is mum is coz i think Shaurya knew that they wont accept him and his help and will hate him due to his mum and he has grown to love the Nanda family.
Another reason is that he is in love with Anjali - so he wouldnt hurt the family coz hurting the family means hurting Anjali as well