Ultimate futility!

Its amazing the things we take for granted in life! Fertility, family, home .......
Most human beings have an almost infinite capacity for taking things for granted - Aldous Huxley

I am back after my treatment, and sadly its a BFN - negative. I am suddenly numbed, jaded and lost. I know I went into this last treatment with little hope, however hope accumulated along every stage. For heaven's sake I even named my embryoes. And my husband expected me to come home last night pregnant!! The hurt and the loss is I suppose almost like a loved one dying, or a miscarriage. How do you console yourself after such a loss?

The only option is to believe ignorantly that God or a higher being up there does not want me to become a parent because I will make a bad parent. What else is there to this? There isnt any more variables such as timing, stress,hormones etc... everything was eliminated during this last cycle. But still a negative.

My question now is when do you know its enough and you should stop trying?

All my life I never failed in anything - great supportive parents, brother and family, a small number of good and close friends, passed all my exams, married the man I love so much and now the failure comes from fertility! Mother nature itself! How to fight something like this?
The down side of this is - to see the pity in peoples eyes, the hollowness, when they know that this has failed and there isnt any offspring on the way.

The only solution is either to die fighting or to surrender to the futility of something like this. So when do you draw the line?