How do i find the inner strength to carry on living life and actually enjoy it?

my ex fiancee is due to marry my best friend very shortly and i just cant accept it. to cut the long story short we were due to get married last year but was cancelled for personal family reasons we still spoke and met up now a month ago she drops a bomb shell saying she has been approached by my Friends family to wed him. his family are happy and her family are also happy i asked her what about you, she goes i will be happy as long as my family are. I just don't know how to accept this because i love her soo much and deep down i know she still loves me but she wont go against her family for me, i dont know whether she is doing this out of spite or hate or whatever but for me its like im attending my own funeral in so many ways as i see the guy nearly every day as he lives down the road from me and im great friends with his brother i feel so betrayed and hurt by this and i dont think i will ever move on in my life because of this for me life really is not worth living anymore