I don't know what I am doing wrong (well I kind of do)

Update, after spending some time figuring out this site, I think I opened my food diary. In veiwing it (more than just the day to day), I think the issue I'm having is some days I eat way to little, and some days I eat too much. I guess on days I eat too much, I try to make up for it by eating too little the next day. Though the former bulimic/anorexic side of me wants to eat very little, and exercise a lot, I know this is bad both for keeping weight off, and for staying healthy. I have lost inches, and while the scale is my worst enemy, my clothes do fit much better. I guess I need to start tracking my food diary better rather than looking at the day to day logs. Thank you for your replies!
Hi all, I need some guidance (forgive me for such a long post, but I want everyone to see the full facts). I have been on a fitness routine for about 2 months. I started slow (doing a stationary bike), but after about 2 weeks of that, I started up on Chalean Extreme. I did Chalean extreme for about 2 weeks, and I was noticing results, but I decided to go a step further, stopped doing Chalean, and started going to the gym. I was doing about 30 minutes of weight training, 15 minutes of abs, and 15 minutes on the elliptical. I did this for about 2 weeks, but then moved to an apartment with a gym. At the apartment gym, I started doing the elliptical for 30-40 minutes, and about 10-15 minutes of weight training (I burn about 275 calories doing this according to my heart rate monitor). Long story short, for the last 2 weeks (the length of time I have been doing the apartment's gym), I have not only stopped losing weight altogether, but have actually gained 2 lbs. Now on to what I eat. For breakfast, I drink a GNC women's vitamin shake. It is a 100 cal. meal replacement that contains all the vitamins I need. For a snack mid morning I eat a piece of string cheese (low cal/low fat), which is 60-80 calories depending on the brand, or a 90 cal yogurt. For lunch I have a GNC lean shake which is about 200 calories. My mid day snack is 1 cup cottage cheese (140 calories), and for dinner I eat whatever I want (usually around 600-900 calories depending on what I eat). Even if I eat a high calorie dinner, I still am at around 1400-1500 calories (some days it's less, and if I go out to eat sometimes it's around 1600 calories). This is my calorie count not counting calories from a workout, which is between 200-300 calories. I cut out junk food, and I have had a total of maybe 4 sodas the whole time I have been doing this. Recently, within the last 2 weeks I cut out all drinks other than Mio water, or occasionally I drink crystal light. Everything I was doing was working for me until about 2 weeks ago, when the weight completely stopped coming off. I only have about 15 lbs to lose now, but I don't know what I am doing wrong. I don't eat any different, and the only thing that has changed is the way I exercise (I still exercise just as much, just a different routine). What am I doing wrong (the only thing I can think of is eating a lot of calories for dinner, instead of spreading it out during the day, though up until 2 weeks ago this wasn't an issue). Can anyone give me some guidance as to what I am doing wrong. I very recently did start running (like 2 days ago), and I am hoping this helps. All your advice is greatly appreciated.