I'm new

I'm a newbie. I'm a 41 yr old mother of 5 and full time student vet nurse. I used to be 110lbs but at the moment I'm 161, and I want to lose 40 or so lbs to get back to ideal for me.
I got down to 126 after my twins 6yrs ago, but it all went back on again a couple of years ago when I hurt my back and some meds I was also on for migraines made me gain a lot of weight - I went up to 182lbs!!! Since stopping those I've lost some but not all through healthy eating so I started a low fat diet since Jan and have only lost 5lbs so far - I used the same diet after my middle son and lost 50lbs so I don't understand why it's not worked this time. My doc sent me for a thyroid test today but if it comes back negative - which he thinks it will - I'll be needing to look at my diet again a bit more closely. I'm also wondering if I may be menopausal.....!!!
As for exercise I ride horses, do yoga, zumba, bellydancing, Morris dancing and walk the dog. We've got a WiiFit, but I haven't used it since Xmas!!!!!

Looking to meet anyone in the same boat as me for some mutual encouragement

K x