Realistic weight loss goals after my first baby??

So I wasn't super skinny when I got pregnant, but I wasn't obscenely overweight either. I am 5'6" and weighed 180 when I got pregnant. I ended up weighing 224 at the height of my pregnancy. I am officially 7 weeks post partum now, and weight 195.6. So I've lost just over 28 lbs so far. Obviously a lot of that was my 6 lb baby, placenta and water weight, but I feel pretty good that some of that is just me losing it.

Guys, I can't even begin to tell you how gross I feel my body looks. I got SO many stretch marks through my pregnancy all over my legs, boobs, butt and belly (I mean really deep dark ones on my super fair skin), and I know there is nothing I can do about the stretch marks, so I'm trying to focus on the weight loss. So... on to my goals...

I am hoping to get from 195.6 to 189.9 by the end of March (is that too ambitious for 2 weeks??), and then by the end of April get to 179.9. Ultimately by July I would like to be at 165... and then by 1 year post partum I would like to be at 145 which was my wedding day weight 3 years ago. But I really want to get to 165 by the heart of summer so I won't feel self conscious being at the lake with my husband and baby.

I just started getting out and walking yesterday for the first time since it's been so cold, but I really don't think I can swing doing a gym... I want to spend my time with my family, but we are very active outdoors (hiking etc), so that's how I plan to get my exercise in... And I have been eating super healthy and sticking to my 1200 calorie goal (thanks to the help of my fitness pal)... do you ladies think I am only fooling myself with my weight loss timeline?? Should I adjust my expectations some? Thanks ladies