I have followed your story a bit, it is sadly a lot like mine. My ex-dh and I tried for 5 years (8 medicated Follistim IUIs and several unmedicated IUIs) with not even a hint of a BFP. We were both tested for all of the common miscarriage reasons and they found nothing. Then I started to get pregnant on my own only to suffer miscarriage after miscarriage. 11 in all. We had every test you can imagine done and one of the last ones my RE did was a (sperm) DNA defragmentation test. It finally gave us our answers. Our only hope at conceiving would be done through ICSI / IVF. We didn't make it that far and after 10 years of marriage divorced. A lot of doctors don't test for the DNA Defrag if you are going to ICSI anyway but if you haven't done this test you might ask for it. If you are dealing with the defrag you will most likely not conceive and carry to term without IVF/ICSI. There is always the chance that you may, if you can endure the loss after loss. I couldn't after 11 losses.
I know the pain and anguish you are going through and there are no words...Hopefully you are working with an RE even if you decide that IVF isn't the right path for you.
Wishing you all the best!