My heart

He hurt me. (if this refers to the man you are talking about this is fine.  If you are speaking of your heart hurting then perhaps better to say something like, my heart is breaking, or I am heartbroken )

Last week, when I opened my facebook, I received a message from a girl asking me to leave his  her "husband" (In English, there is no agreement with the noun, it is with the subject so "she asked me.." therefore it is her husband) alone, in fact he is not married, maybe he is engaged. Anyway, we have been having a relationship for three years now. He told me that he loves me and that he want to be with me, but he was a liar, he broke my heart and I am suffering now, I don't really know what to do.

This is a very good but very sad diary entry, with very few minor errors.  I am really sad for you Arsene, sorry to hear that your heart is broken.  Three years is a long time to have somebody lying to you, he is not worth your broken heart. Be glad you are free of a liar and a cheat, if he lied and cheated with you whilst he is possibly engaged to another girl then he will do it again.  Be sad for her that the man she trusted has already lied and cheated.  I hope you find an honest trustworthy man who deserves your love.