There are so many women here, and on the Pink Board, who have had multiple failures and who have finally found a way to become mothers. You are unbelievably strong to have spent the last 12 years in pursuit of motherhood. I would not have had that kind of strength. So, it's OK for you to be scared, and to be torn between giving up and moving forward somehow. It's ok to not feel strong right now. I have a book called, "Feel the Fear and Do It Anyway", and that's my advice to you right now. No one can guarantee this cycle will work, but if you don't try then you may feel regret the rest of your life. There are times when we need to somehow motor through, just putting one foot in front of the other. Find a Yin yoga class or a fertility yoga class if you can. It will help reduce the stress and balance your emotions (I teach yoga so I'm a bit biased here, but there is research behind what I'm saying). Acupuncture saved my life while TTC, so if you haven't tried that yet, it is well worth it. It doesn't matter that you're not using your own eggs. Do whatever you can to support yourself. For me, having some clear back-up plans kept me sane. We were willing to foster adopt if needed and I knew that was always an option. I know there aren't many donor embies out there, but if that's an option you can get on a clinic waiting list. Those are "affordable" options.
My heart and prayers are with you. Keep us posted.