TTC baby #2!!...??!!

My baby fever has successfully won over the husband! Hizzah! Victory! But a long with such victorious celebration comes fear, anxiety and what if's. I made an appointment with our geneticist for the first week of November and assuming all is well, we will proceed with said baby making. If all is not well we plan to adopt instead. I cannot mentally, physically or emotionally go through this again. I think it would be selfish of us to try for another baby when we KNOW there is a genetic disposition, I cannot and will not watch another one of my children struggle through life and get frustrated with their limitations. I love Naysa and all she has taught me, who I have become because of her but I would also like to experience pregnancy with innocent excitement and easy fears like "will I be a good mom" rather than "will my baby live for more than an hour." I'd like to know what it feels like to spend a relaxing day at home with no therapy to go to, to see the wonder of a child who experiences those milestones that I would NEVER take for granted. I would also like to be more excited than fearful when it comes to TTC but that is obviously not a plan He has for me. I worry about a lot of things, most of them irrational. Like, what if I love my (God willing) typical child more than Naysa...what if I start neglecting her therapeutic needs because of the new baby or how will it feel when my new 9 month old is surpassing my little bug? On the other hand, I have heard that having another child can help a special needs child developmentally, the baby could teach her things and she could learn by mimicking. Maybe I won't feel so short changed about Naysa's development because I will have experienced it through another child and be even more proud (if that's possible) of how far the bug has come? I know most of this is ridiculous and I am mostly rambling to myself via typing but it helps. November 6th couldn't come soon enough!