Concerned I am losing too much.

About a month ago I was 275.2 lbs and 5"3, and set out to loose about 1.5 lbs a week. In the first three weeks I lost about 8 lbs, but in the last week or so my appetite has been very low. About a week ago when it started I didn't feel hardly any hunger and that's why I didn't eat that much. I've started to feel hunger sometimes now, but it's like I don't wanna eat. It's hard to explain. But in the last six days (I just weighed in) I've lost 7.5 lbs, and that is NOT OK. I don't wanna lose weight that fast, because I know it's not good for my health in the long run. I'm bringing it up at my next doctor's appointment to be on the safe side, but in the mean time: should I be concerned, and what can I do to bring my appetite back up?

PS: this kind of loss of appetite is new for me, so it's not a part of a pattern and even though I did step on the scale three times and got the exact same number each time, I have not yet ruled out that it's a scale malfunction (cheap piece of s*it from Kmart!).