How to get back with my ex even though she has a man ..?

well here my story .. i went out with this one girl.. then i lost her and ever since ive been heart broken and still love her... now these days i always talk to to her and make her feel like that im the only one she shud go out with.. i make her laugh, cheer her up and stuff .. anything i can to make her feel better.. but then she has a man now.. and she tells me hows shes happy with him and **** which all makes me want her more.. all i want to ask.. is what shud i do to get her back?? if not then what can i do to even make her think about it or something or take it into consideration .. overall peopls i cant live w/o .. i dont want to choose anyone else... : ( please helpp .. thanksHow to get back with my ex even though she has a man ..?
juss be her friend..and let her know..that no matter what you'll always be her friend