I hope you're wrong and the period isn't a period afterall, but I'm so sorry you're dealing with this. It is an incredible pain every single time. As for how to keep going despite that, for me it was simply that I couldn't accept the alternatives. I was always acutely aware that to stop doing IVF meant choosing another reality- childlessness, adoption, DE- and I was not ready for any of these options (even though I think they can be great ones, more on this later). My tubes are scarred so TTC naturally was never a real option for me, and I felt the pressure of time and increasing age and knew that my best chance for success was doing everything I could to get pg when I was as young as possible. I essentially kept going b/c there was no other palatable option for me at the time.
Now, if you're asking how to stay sane during the process, I'm not entirely sure I did (of course, I'm not really sure that I ever was sane, but that's another story...
). I think that trying to remember that going through this is impossible and more than anyone should have to bear when trying to have a child is important- giving yourself a break for not feeling sane was important for me. Talking to others who know what it's like (like on this BB!) and perhaps an IF therapist can help too. Also, doing small nice things for yourself- linger in a coffeeshop, get your nails done, read a trashy magazine in the sun, take a walk in nature- it's important to do these things to re-energize yourself and to be reminded that all
of life does not suck. Finally, I always spent time on our sister DE boards and looked into adoption. Although I wasn't ready to do it myself (I was actually getting there during my last cycle) I found it helpful to look over there and see that there was another excellent option available if and when I became ready for it.
As I said, it's an impossibly painful situation to go through and it's often a prolonged process which doesn't help. Wishing you luck and sending you strength.