A little help, please?

Dear lovely people, you...

I stand between 5'3-5'4, and my long-time current weight wavers at 133-135. My bone structure is very small and I love being agile and free to move/dance/climb trees/etc. without any excess weight in the way. Thus, my ideal weight is 110-115 -- meaning, I'm starting with a goal of 120 and feeling out what's healthy from there. I have desired this change for the past few years, but have failed to ever be determined enough in my habits to reach it. However, in the process, I may have developed some unhealthy habits along the way.

To begin with: it is possible that I habitually undereat. I have essentially been on a 1200/1400-calorie-per-day lifestyle for years, though my weight has also remained the same throughout that time. I would like to eat more to increase my energy, but if I eat more, I gain. If I eat any less (I do not deliberately go under 1200, but when I am not tracking myself, it is likely I eat less), I get hungry, tired, and very depressed. My personal response to anyone else in this situation would be, "Eat more! Your body will adjust and start to use the energy rather than store it." Funny, isn't it, how when it's our own bodies we're more frightened to take our own advice? I find myself in need of other peoples' words to guide me this time. Any wisdom is welcome.

Food. I am very healthy, home-cooked, and non-processed in my food choices. My difficulty lies in scheduling my meals. If I eat three meals a day, I feel satiated for a while but tend to get hungry by the next meal--hungry enough for my emotions to be affected, and to go ahead and eat something before I planned to. This can lead to me consuming far more calories than I will use during the day. Also, if I eat larger meals, my stomach becomes bloated and remains so throughout the entire day. (Same if I make a habit of drinking enough water daily--help?) However, if I eat my food sparsely but consistently throughout the day (small snack-like meals every 2-4 hours), I am able to eat more often, but the small portions also leave me feeling like I've never truly satiated myself. Hence, I feel hungry all day, and though I am feeding myself, I am constantly empty-feeling, food-minded and uncomfortable. Surely there's some way to feel satiated without eating once every hour?

Exercise. I recently became a waitress, so my days are full of movement. However, this makes me unmotivated to exercise additionally on work days, or at all on the weekends. To be honest, it has boosted rather than depleted my energy, for which I am grateful. So it is not so much that I feel too tired to exercise, as it is that I dislike the thought of using the little time I have to myself for exercise. Waitressing alone has not resulted in any weight loss. Again, surely there is a balance that will keep me both rested and active without making my entire life revolve around exercise in some form?

In short, my perspective and my habits may not be as they should be, and I would love to start taking better care of myself. I would appreciate any insight, counsel and encouragement that might be given. Thanks you guys. ^.^