I partly agree with you. I see it two ways here ...
1) If we take the characters as written to face value then one has to think that neither of these two have really changed, have they? Zoya still goes on making her own decisions. She might always have Asad's best interest in mind (i.e. helping his sister, helping his mom, etc.) ... if only she would wait for him to come around (which he mostly does). On the other hand, Asad might love Zoya, but she always plays second fiddle (to his mom, to his sister/brother .. or maybe it's to his own sense of responsibility that he carries around for these people).
Or
2) I personally think that Asad's character is a bit poorly written. I never really bought the explanation given to Asad's behavior when his mom first suggested that Zoya and him make their engagement official -- i.e. Asad was afraid that he would would hurt Zoya the way that his dad hurt his mom. Well that made no sense to me. Couldn't he just ... um ... I don't know, not marry another woman?
I think the writers missed a real opportunity here ... they could have shown that both Zoya and Asad have abandonment issues, but they both deal with it in very different and almost opposing ways.
For Asad, it would explain his OCD as his way of controlling what he could control. It would explain why he wouldn't want to get involved with Zoya as she would potentially be the one person in his life who he could love, but could never control. So his fear-based subconscious would focus on, what if loved her and she left him? Everything else would just be a cover-up story his mind had told himself .. like she has no tehzeeb, not the right person for my family, etc. etc.
It would explain why he was so ready to let Ayaan borrow her. Zoya leaving him on his wedding day, only to get married to his brother ... it was sort of the ultimate abandonment, right? If you go back and listen to some of the dialogues of that day, Asad says something like ... "well you are already married and my sister is sick". So her abandonment of him is first on his mind and then his sister's sickness. I almost felt like the things he did that day were half out of anger and half out of responsibility.
This would also certainly explain what he did today ... it was his "you're not leaving me, I'm leaving you" bit. That's why he didn't stop even when she pleaded.
I think they could have shown Zoya with the same abandonment issues. That way I would cringe less when she forgives, begs and pleads so easily. At least we would know it's because she is afraid of losing anyone she even slightly cares for.
Then it would have been interesting to see how these two come to a place where they can love each other without fear.