Some advice needed?

Hey, I'm new here! I was just wondering if someone could give me some advice. Over the past 3 years I've gained a lot of weight. I'm not sure how much because I never used to weigh myself. I never needed to because I wasn't fat. Now I am, so this weight loss stuff is new to me. I'm currently 189 pounds. Last summer I was 207 pounds(my heaviest) and at Christmas 2011 I was 182. I lost 25 pounds between September and December by restricting my calories and going for walks. Then Christmas came around and I got lazy. Between Dec and now I've only gained 7 pounds but it feels like so much more. I want to lose at least 20 pounds by September but at this stage I don't feel like I'm ever going to lose the extra weight. I'm so depressed about how I look that I barely leave the house, and if I do I end up getting extremely stressed and anxious about seeing people that used to be in my life. I'm only 20 years old, so going from a thin teenager to a fat adult has left me with no self confidence whatsoever. For the past week I've been eating around 1200 calories(sometimes a little more, sometimes a little less) and going on a brisk walk everyday for at least 40 minutes. I weighed myself today and I've only barely lost two pounds. I feel like I did so much hard work and it's getting me nowhere. Should I be doing more exercise? Eating less? Eating more? Some advice to keep me motivated would be really great. I'm sorry for the long rant. Just feeling a bit overwhelmed.