For the last one month we have been seeing Milsi ask himself why he hated Prachi so much when she is so nice and of late he has also been asking himself why he is drawn towards her and feels miserable when she is not around. I feel he should concentrate more on the first question he raised - why did he hate Prachi so much - for him to regain his memory because therein lies the answer to the second.
Why did Milsi hate Prachi? Granted she was the sister of the man who ruined his sister's life. But that was not the main reason he hated her in the beginning. In fact he did not come anywhere close to hating her. He despised her because she was from the Shah family. Other than that he did not have any strong negative feelings towards her. He even was willing to help her find her father's murderer.
His feelings really took a turn when he found out that Ayesha left him to marry Neev and exact her revenge against Prachi. It infuriated him that Prachi was not firm enough to hold on to her love for if she had, Ayesha would not have left him. So a combination of factors such as taking revenge against Ayesha, punishing Prachi for her helplessness and teaching Alaap a lesson led him to force a marriage of compulsion on Prachi. Soon the feeling of hatred turned into jealousy when he thought she was still holding a torch for Neev. The jealousy strengthened when he realised that he himself had fallen for her goodness. Somewhere down the line, amidst all the jealousy and love, he completely got over his hatred.
Now considering that Milsi has lost all memory of Ayesha's marriage to Neev and his own marriage to Prachi, there is no valid explanation for his anger and hatred towards her. If he had felt it then it was lying latent in him because of what had happened to their lives following Ayesha's revenge. That is why I would prefer to see him repeatedly ask himself the question as to why he hated Prachi before. In searching an answer for that he may recollect how Ayesha betrayed him and how he ended up marrying Prachi because at the end of the day that was what triggered his anger and that was what led to his subsequent falling in love with the woman he used merely as a pawn in a larger revenge game.