I was too old to try with OE when I started ttc, so I had no choice but to go to DE, but "addiction and cancer and mental illness race through my family on both sides like wildfire" is also an excellent description for my family (except less so the cancer and more so autoimmune problems), too. That was one huge element of my reluctance to have kids when it was biologically feasible for me to do so. In the absence of a high order genetic illness like Huntington's or Tay-Sach's, people tend to be dismissive of concerns about potential genetic issues. Even so, we had a young woman on this board a few months ago who actually gave birth to a naturally conceived child that had a serious genetic illness, and when she and her husband decided to use DE for their next child, her family gave her grief about it. People are just screwy on this subject. When I mentioned this as a concern to my RE at GIVF, he actually characterized our using DE -- never mind that I didn't have a choice at my age -- to avoid these issues as "eugenics."
I think it is possible to want kids so much, you're less concerned about the child being your genetic progeny than having a baby, because I was, too. Incidentally, as I mentioned to the woman going to DE due to her naturally conceived child's illness, I guess about eighteen months, two years ago maybe, someone meekly posted asking if anyone thought it was a bad idea to go straight to DE in her circumstances, and no one, no one said they thought it was a bad idea. That's b/c there are so many women on this board who just drained themselves emotionally and financially on OE before they finally decided to move on.
I will say this, I posted on the pink board recently b/c I had a little surprise grief attack when I had a get-together with a mom's group, most of whom had conceived through IUI or OE/IVF, and it suddenly struck me that they all resembled their kids, while I don't. (Now, that's partly b/c I cycled overseas where donor coordinators choose your donor; even the other woman in my group who conceived through DE w/GC looks more like her kid, b/c she had more control over her donor.) So, your emotions can surprise you later on.
I think you're just being realistic, and this is just such an emotion-laden process that most people can't do that. I would say follow your heart. I know I didn't think emotionally I could do more than two or three cycles. Thank heaven I got pg on the second one.
Good luck and take care!
Maggie (in VA)