I don't think 10 lbs is reasonable, and I don't think you should stress yourself trying to stick to that.
If you are bordering obese, the recommendations are 15-20. Sure YOU may be overweight, but your baby still needs the nutrients.
I gained about 70 with my first pregnancy and my doctor didn't care. I was slender to begin with, but quitting smoking packed on the lbs in the first few months. I was monitored and healthy. My second one I gained 80 and my doctor was HORRIBLE about it. Mean. I used to hear the midwives laughing about me outside the room and the I would leave there in tears almost every time I went because of the comments about my weight. I was a size 2 before that pregnancy, and again quitting smoking packed on about 40 lbs in the first 5 months.
I didn't lose the weight after my youngest and as a result I am starting this pregnancy 30lbs higher than my ideal weight (I've gained 4 lbs already and am at 154 and 5'3)
My midwife didn't say a word about my weight yet, though I am definitely in the overweight category.
Look, I get that you have to be careful with weight gain. I had VERY large babies (8.12 and 10.12). It was MUCH harder to lose the second time.
But instead of concentrating on weight and numbers, what I'm doing (aside from my new french fry addiction) is trying to focus on eating well - whole, local foods. And getting activity. My first time, when I gained 70lbs? I walked 5 miles a day at least 4 days a week until the last month. I was huge, but I wasn't really unfit.
I wouldn't recommend ignoring weight totally, but it shouldn't be your focus OR your doctors focus. It should be on maintaining healthy eating and a healthy lifestyle.
Oh, and I would consider seeing a different doctor - just from my traumatic experience with a weight concerned doctor.