Well if the promos are to be considered,there seems a probability building up....that Anurag attempted a suicide because he failed to find the true love of his life...and by the time he relised his passion for Taani...his childhood friend it was probably too late...As far as yesterday's episode is considered,both of them consider thier marriage fake and not really a committment.So quite possible that Taani was compelled to get married to someone else,when Anurag chose to fall for another girl.
it was also mentioned in the first epi that nobody has come to meet Anurag in all these yrs,which may be because they presume him dead...and when Taani discovers Anu she is there for him immediately.....
The reason of Anurag losing his sanity might be that not only did he lose his Taani but at the same time forced her into a marriage which she probably never wanted...that is this might be his own feeling of guilt that wrenched out his sanity.Though quite possible that some miscommunication might hav taken place(as is always the case in most BT serials) and while Anurag might have presumed Taani is now married.Taani might never have really married anyone....
I know these are all just speculations...so just let me know what are your views....