iv just thought of something ......maybe nitesh and gauri loved each other. This is what i think gauri's past could be, nitiesh and gauri loved each other but nitesh, he was totally crazy about gauri and one day gauri's father told her that he has chosen someone for her and he wants gauri to marry him (which was shansker i think i spell that wrong ๐) and gauri could never say no to her father so she agreed that she will marry shansker so she told nitesh and he couldnt take that so he became total mental ๐ not as mental person i mean mental in love, and nitesh kept telling gauri that if she doesnt come back to him he will himself and he kept doing some things which scared gauri and gauri told nitesh she never wants to see him again.
OR
they went to same college and he fell in love with gauri and ever since he keeps following gauri like mental stalker and kept doing things which scared gauri ...likeeeee write her letter which was written by his blood ๐
guys this is ekta serial so these things can happen ๐