I HAVE A LOVER 6 MNTHS AGO HE TOLD, HE CANT MARRY ME BUT WE STILL HAVE THE RELATION WHAT SHOULD I DO? ?

i cant live without him, i deeply love with him but for some mental changes he dont want to marry me.we are best friends but when he talking about his maariage i cant hear that it's really painfull for me how can i solve this problem.