Question Summary:
I have been talking to the opposite gender. What should I do to save myself in this world and the hereafter?

Question Detail:

 
I am a 27 year old boy working in a marketing Company in J&K India. I have got my engagement  to a cousin sister sometime back as per my parents wish, but was not able to marry because, I was posted out from my home. Now I have been transferred to my home town and my department has also got changed. Earlier it was Company to Company dealing now it is public dealing.
 During my public dealing one of my channel partners(Customer/dealer/reseller) whom I met was a young lady having age about 25, but she is handicapped and can’t walk on her legs.  In terms of official language I am her boss. Right from the first meeting I got very sympathetic to her and usually tried to encourage her, because she is handicapped and her business unit is defunk for about last two years.
She usually called me up on my phone regarding the business unit and discussed the possibilities and options to review it again. And at times I also called her.
During the conversations over phone she liked me and started loving me. Slowly and steadily the frequency of phone calls increased. And her intensity of love increased to such an extent that whenever, I told her that I will marry someone else, she was never ready to listen and accept it. As soon I tried to say her about my marriage, she could not bear it and her health condition started deteriorating. I got scared that if I told her suddenly about my marriage with somebody else, she would suffer from a heart attack and would die immediately. Even she suffered from a minor heart attack, when she suspected that I am going to marry somebody else.
I decided to prepare her slowly about my inability to marry her. And  strategy  I thought  was that I would tell her that my parents are not ready about our marriage. After thinking a lot, I finally went with this option, because I had to tell her that I could not marry her.
But to my surprise, the moment I told her that, my parents are not ready, She cried and screamed and since then till date she is crying, weeping and hardly eating anything. She had been hospitalised  twice in 15 days. She was shocked and is not able to recover since then. Currently she is suffering from the shock, which had lead to some heart problem and most probably she might be having heart surgery, and her condition is very critical and is not able to sleep, even during nights.
Now she is telling, infact threatening me that, She will take revenge from me, of all the pain that I have given her, on the day of Judgment, which makes me very painful and un-resting. She texts me very horrible messages that Allah will take revenge from me both in this world as well as in the world after death for which she makes duas also. She even gives me references of her dreams,  that some prophet came in her dream and told her that, the persons who had lead her to such a bad and pathetic situation will be thrown to hell.
I am totally frustrated and don’t know what should I do. I would be highly thankful if you would tell me what to do. Give me some suggestion/opinion so that I can:
Save myself on the day of Judgement and in this world also.
Save her from the critical and painful condition through which she is suffering.
Get married to the cousin as per my parents wish.

Whole story told above started about two months ago. I also consulted one of my friends who advised me to avoid her by not answering her calls. We don’t talk over phone now. But She texts me horrible messages on Whatapp, that Allah will take revenge from me in both the worlds because of the pain that I had given her.
Please guide me what should I do, so that my both worlds are protected.

Answer :

In the Name of Allah, the Most Gracious, the Most Merciful.
As-salāmu ‘alaykum wa-rahmatullāhi wa-barakātuh.
According to Shari`ah, one may communicate with the opposite gender only if there is a need. In that case, the discussion must be confined to the need. 
In your case, you have transgressed the limits of the Shari`ah and spoke to the girl more than the need. Both of you are equally responsible. You should make tauwba to Allah for transgressing the limits of Shari`ah and also for possibly misleading her. You should stop all communications with her immediately. She is an adult and is responsible for the consequences of her wrong just as you are responsible for the consequences of your wrong. In future, exercise precaution in dealing with the opposite gender. 
You should consult with your parents regarding your marriage and also make istikharah. 
And Allah Ta’āla Knows Best
Hafizurrahman Fatehmahomed 
Student Darul Iftaa
Netherlands 
Checked and Approved by,
Mufti Ebrahim Desai.