For me it was important to understand once I had done everything I could do...it was largely a crapsoot as to whether or not I got pregnant.
I had 2 successful pregnancies from 5 cycles. Maybe it was donor egg/sperm issues, lining issues, diabetes or some TBD issues. I don't really know why it did work OR WHY IT DID NOT. None of my Dr.s do either. For me, realizing it was a numbers game and SOMEBODY had to be on the losing side of statistics was comforting. Having said that, I chose a clinic that had an almost 70% success rate, even though that did not ring true for me personally. My own rate was a 40% success rate so I just tried to persevere and not take it personally.
I tried not to get too invested/involved because I just couldn't bear more failure after all the years of my OE IVF's. I was pretty mechanical in following the protocolls, going through the motions. It was self-protective after so much loss.
I also deliberately chose a clinic where I could afford multiple cycles. I did not count on it necessarily working the first time around, just because I had been on the fertility rollercoaster for so long, and I was used to things not working.