Carrie,
Don't get down on yourself. I stayed in the 170's for 8-9 months. It sucked! I got discouraged but I never gave up. I tried everything I could think of to break out of plateau, but nothing worked. I bought a pair of Skecher's Shape up shoes. They were so comfortable that they motivated me to walk more often. They don't seem to have done much for my backside, but my legs are now super-toned. But, I still wasn't losing. I cut my calories down to around 800 per day. It was tough, but I was desperate. I am not really recommending it, but that is all that worked for me. The scales started moving again. It is still really slow, like only 1/2 lb. per week or so. I am trying to stay around 1000 calories per day now, but some days I still only do 800. Hope the personal trainer works out for you.