Yes, looks like the damage has been done and getting worse day by day. The only reason why it looks fake is, he gets emotional every time he hurts Kavya or her family (it was evident yesterday as well, when Rajiv lashed at him).
I think, there is some conversation/communication between Omi and Adi before his death (like he sent a voice msg to Alka, may be sent something to Adi/left some note before going to meet Kavya..etc.).
May be Omi told Adi that they will kill Kavya (he told the same to Kavya also, and did not reveal the partner's name). May be he asked Adi to save her life at all cost and Adi is trying all possible things to do that (doing everything which can hurt her). May be there is some last wish of Omi, which Adi trying to fulfill.
(there is a small hope that, the makers/writers cannot ruin Adi's character so badly, how can they destroy such a beautiful character/the show)
Yes, even if its true, the makers have dragged it too far. Now, there is no hope of faking hatred story. Because, once Kavya finds the truth/Anurag's involvement in Omi's death, then there will be no use of this faking hatred story and it will not make any sense.
Only hope is Kavya finds the truth behind Adi's faking hatred story somehow (may be somehow she finds that Adi knows about her being innocent). If she does, then it may make some sense and viewers can connect back. Otherwise, even if they run any kind of redemption for months, it will be difficult to bring back old Adi.