WMDO - glad to see you are back, but very sorry to hear about the thyroid problem. I can totally understand the freaking out. FWIW, anytime I get something, I google like mad . However, Aunty CTOFN is now going to give some stern words to my friend WMDO!!
My cousin has this. It was diagnosed, ooooh, probably about 10 years ago now. Again, just through being mega tired, although that really doesn't describe the feeling, does it? Anyway, she is FINE!!! She takes medication for it, but hey ho, I take inhalers every day for asthma and anti-histamine for hayfever every day April-September. You get on with it. Life's a bitch... and then you marry one as my ex husbands have always said to me .
Now as for this silliness about what you've done to Olivia !! YOU HAVE DONE NOTHING!! You have not intentionally taken drugs, smoked during pregnancy, got sh*t faced every night during pregnancy - anything like that at all. You had an undiagnosed disease that you had no control over whatsoever. Whatever Olivia turns out like later in life, you will love her just the same won't you? My DD (7) is brain box of Britain... my DS (11) is absolutely not . Below average actually. I did everything right in the pg with DS and everything wrong with DD. Including their health. DS had asthmatic tendancies as a small child. I could not give up smoking with DD - she has NEVER had a problem. You love them both the same anyway.
My point is, that these health things don't always come to light. Sure - the medics have to say, ooh, there is a chance of this and a chance of that. I had to sign a disclaimer for my c/s that they MIGHT cut through my bowel... and my bladder etc. They didn't.
Do what you can to get your own health sorted, particularly the pains in the chese. Do go and see your GP asap, sit and have a good heart to heart about it (forgive the unintended pun there). But PLEASE PLEASE PLEASE do not blame yourself and think you have done something to your children.
You may hate me for the "tough love" post above. But if you want to talk/email etc offline - email me on CantThinkofFunnyName at googlemail dot com.
xx