Glynne - glad to hear you're feeling better physically and are in better spirts mentally. Now you're on an upward swing everything should start falling into place and you'll be back on your way with a vengence
BlondeAmbition - do you live in Canada or Britain by any chance? Although I think the posters here have explained the muscle vs fat issue very well in respect of clothing size, it also makes a difference where the article of clothing is made. I'm in the high 150s (finally) and wear size 10/12 Canadian made, but on my last trip to Buffalo purchased a pair of pants in size 7/8 that fit fine, so I can certainly see how a TV spokesperson could wear a size 7 at 150, and I doubt it's false advertising or exaggeration.
I sympathize with your problems and understand the difficulty of adjusting to being overweight after a history of normal weight, but even if you can't revert to your former self (and physical limitations aside that would be difficult by reason of the aging process, childbirth, less opportunity to participate in prior activities) you can still learn to eat properly and lose weight slowly (and I consider a 2 pound a week loss tremendous - think of what that totals in a year) and above all improve your overall physical and mental health.