How do you know when to move on?

I wish I had started this years ago to fully capture this 5 year journey I've been on so I could look back and remember the emotions and feelings I have experienced. I guess now is better than never.....
To want something so badly but you can't have it. It's a feeling that I struggle finding the words to describe. The realization that I may not be a mother, to not share something so sacred with my husband..how does one deal with this? I don't know....the frustration, the anger, the hurt, it is all becoming more and more overwhelming. To not succeed at something...to fail, my body has failed me....and to not know why is the hardest part. How do you know when to say enough is enough and move on? How do you know when to throw the towel in? I don't.....

I've been to 3 different fertility doctors. I've tried Clomid 6 times and have tried injectible medications 4 times. I'm up to 11 IUIs (artificial insemination). I had a laparoscopy where they discoverd I had deep endometriosis along with a slew of other issues-polyps, a blocked tube, this after being told that a laparoscopy "wouldn't show anything that could be affecting my fertility"-good thing I sought out another opinion! The "good" news in all of this is that I did conceive after they cleaned me out inside. But I miscarried after 7 1/2 weeks on Mother's Day, after just hearing the heartbeat. I was left thinking that maybe that was my sign...maybe this isn't meant to be. How could "he" be so cruel? Maybe the signs have been there all along and I'm refusing to see them.

On my quest to find answers I went to my fourth doctor last week who basically said my ovaries were like "that of a 39 year old". Not something you want to hear as your 33rd birthday quickly approaches. My only hope, if there is any hope, is IVF which of course is NOT covered in the state of PA or by our insurance (after we've already spent thousands on the other treatments). I'm left with the knowledge that I can spend $12,000 for the "hope" that it will work, not even a 50/50 chance especially with my background. Yes, the end result could all be overwhelmingly worth it but what if the results are not +. Am I prepared for the second biggest let down of this 5 year process? I am being consumed by this, by the quest to find answers, consumed knowing that my "biological clock" is ticking away, consumed knowing that although I'm only 33 and should have a few more years left the reality is my body is not 33 but approaching a 40 year old and the success rate is considerably low. I don't know how to see the positive side when the reality is hitting me smack in the face. There is such a void in my life and there is only one way to fill it. I feel unfulfilled personally and especially professionally because I know what my purpose is..to be a mother. I don't know where to turn from here. This isn't the life I planned. My life plan is off course and not being able to control it is so hard for me. I can't let go of not being a mom. I can't deal with the realization that I may not give my parents another grandchild, that I won't see what Eric and I could create....How do I get closure? How do I move on?