Back on track?

So I am a little under 5'4", female, 23 (almost 24) and currently weigh 158 pounds.  I started at 180 about 6 months ago and everything was going well.  I was losing slowly because I eat out a lot and took a weekends semi-off (but not over doing it).  Despite this, I was happy with it because I did not have to sooo dramatically change my life. 

Morning breakfast/snacks would be around 300-400 calories. (cut cal during the day a little more because i usually have a more calorie heavy dinner)

Lunch I would either get a salad with chicken (no dressing) or subway (ya know, the 6 inch 8 grams of fat or less deal)

and throughout the rest of the day i would have maybe 2 more small snacks (ex. a piece of fruit or a serving of nuts)

then i would eat a regular dinner (whatever my mom cooks)

I would go to the gym around 3-4 times a week for about an hour mostly doing cardio, some weights.

HOWEVER, i dunno how I got to where I am now...but the past few weeks (about 4) I eat less than 200 calories for breakfast, salad for lunch no dressing and an egg white or 2, my mom's dinner and I started going to the gym during my lunch hour (i started only doing weights but that transgressed into doing cardio mostly) and I go usually 4-5 times a week to the gym AFTER work as well.

well...surprise surprise, my weight loss has halted.  I have only been able to lose 1 pound these past few weeks.  (why did i try and fix something that wasn't broken!)

So now I am trying to get back on the same diet plan I had started with but I am really nervous I am going to gain a bunch of weight back...any advice?

I don't think you are eating enough.  You are working out a lot.  I have this problem too because I started working out a lot and my weight loss stopped and some days I am starving on the lower amount of calories.  Re-evaluate how many calories you need with your higher activity level.