I'm male, 33, 180cm, 172kg, and thanks to lurking in /r/loseit, I've been trying to make some improvements. I have a couple of questions and I'd like to get loseit's opinions.

I'm a graduate student and my university has a very nice rec center. So far I've mainly been walking the track. However, the rec has personal trainers that the students can hire for what I've been told is much cheaper than if I went to a large chain gym. I can get 16 session for about $300 or so. Our semester happens to be 16 weeks, so I would see a trainer once a week. Is once a week good enough? I have a little bit of spare cash to purchase a 16 session package, but I don't think I could afford any more than that. Is it worth spending the money, or should I just save it?

My other question is about reducing my caloric intake. For one week, I ate what I normally would and using the Lose It! app on my iPhone, I found that I eat anywhere between 3000-6000kcals in a day, which obviously explains my weight. I've been trying to get rid of the unhealthy processed boxed foods and restock with lean meats, lots of beans, nuts, fruits and vegetables. Lose It! suggests a daily calorie budget of 2870kcals for my current weight. However, when I eat that many calories or fewer (sometimes what I plan to eat doesn't get me there), I find that I experience side effects. For example, after a meal, I feel full and fine, but then a couple of hours later, I get terribly hungry. But, it's not a hunger that comes on slowly. It's one minute I'm fine, and the next I feel like I'm going to fall over if I don't eat something. Even though I'm not diabetic, I checked my blood sugar and it was fine. Also, after walking on the track for about an hour in the rec center in the evening, I feel exhausted and must sleep. Am I doing something wrong, or is this normal for someone trying to make corrections? Otherwise, I feel fine.

If you guys have any ideas or opinions, I would love to hear them. I look forward to losing weight with you. The stories that I've already seen have been very inspiring.