Send notice for nominal damages to ex-partner.

I had been in a relationship with a girl for 4-5 years. In the course of the relationship, my girlfriend had assured me and my family of marriage, because of which I went all out for her in terms of time, money, and all of myself. Two instances occurred, wherein she confessed to cheating on me, and after the 2nd time, she decided to dump me. As a result of this, I've suffered a great deal of emotional distress and sleep and appetite related disorders. The main reason being the long time period she had been with me and all the things she made me do for her. I would also want to add that I had been physically assaulted by her, not only in fights but also during sexual interactions. She had also lied to me that she was pregnant and threatened suicide. Series of lies were told to me, wherein her phone number was changed, she has gotten involved with another guy. All this has left me utterly depressed. I've been undergoing counseling sessions from the last 6 months, and have spent a great deal of money on that too. I wish to send her and her family a legal notice for nominal damages for causing emotional distress, physical assault and asking them for an apology. I have in possession, all text messages of her over 4 years, many of them abusive and sexual in nature, along with some private pictures she had sent on her own. Only to prove that we had a relationship and it was a sexual one. Also I have in possession my debit card statements, which show the money I've spent on her over 5 years, including purchase of a mobile phone. All this I did by my free will, but only because she had assured marriage. Also I'll my my counselor and friends to give statements for the same. I understand that my case might not hold good in the court, but my primary interest is to send a legal notice asking for apology. I want to know the procedure to go about it and the possible expenses which I may have to incur in sending the notice.