How Much is there to Bear

lets start it like this i am an ordinary guy who loved someone at the wrong time for this love is not allowed for some circumstances. she love me too even though she know the reason and know the situation... but i made a mistake a mistake that i cant no longer bear... i have not informed her with my plans for i don't want her to get hurt... but in the process of that i hurt her instead. and she returned to the one she loved first and this time the love for them become more stronger that even the love i am prepared to give her does not suits it. i wasted a good chance and a good love... even though she said just wait... for they also have issues now... but i cant help myself i am hurting so much so much mo i can bear... how painful pain should i feel before i would give up...

listening to her stories about what they did what are they doing and what are they planning... being there when she's down and taking all the blame if they have quarreled... watching her edit their slides with the photo of them being happy... hoping that she will be happy with me too... hoping that someday her love will comeback to me and hoping that i will be one she is talking about... at what pain should i have to feel at what pain should i have to bear... at what pain at what extent should i bear... i cant leave her for i need her but she doesn't want me to stay... i cant stay away from her because i get my strength from her... i cant loose her i must not loose her but what should i do if she wants me to loose her...

what should i do...
HELP ME PLEASE