Maya, I loved your views, and must say I agree completely. The inward battle Prem was fighting was indeed between his happiness (his love), and the happiness of all others (that he keep with tradition and live up to the values he's been brought up with).
He chose the happiness of other because it was the right thing to do. But, he couldn't just turn a blind eye to Heer and let her walk into her own demise. All he wanted was to ensure her happiness too...He wanted everyone around him to be happy...only then could he be comfortable throwing his own life away. There would be no point to him marrying Ash if he couldn't ensure that everyone dear to him was going to be happy with said decision. Also, at the time, lets not forget that MM's truth had not come out to Heer yet. So, he thought, forget trying to wed Heer, it was much too late for that and too selfish for the likes of Prem, he would instead just insure that she was happy, safe.
It wasn't until the very end when he realized that he was free from his obligation to Ash (when she refused to marry him), that he felt he could perhaps fulfill his own wishes. Though, I think maybe he was a bit confused here...just because Ash let him off the hook, that didn't mean he could now go against tradition.
And to top it all off, in the end, his father told him to take Heer with him...otherwise, he probably would have left her there, atleast for the time being, and walked away empty handed.
Thank you for your views, Maya. I enjoyed reading them.
Love,
~P