I started at a similar weight to you and had lost 23 lbs two months out from surgery (about 10 lbs per month). My surgeon and nutritionist told me that I was right on track! (They based that on the percentage of excess weight that I had lost, as is the standard.)
My weight loss has stalled a bit now but it has been slower all along than others have experienced. That being said - I feel good and don't have many problems with loose skin I like to keep data about my progress, then I can make things like graphs to visualize it. So far, I think it is helping (even though I missed weighing myself for a week). I guess you have to figure out what works to motivate you.
I am not your doctor, of course, but it sounds to me like you are doing okay.