Hey Emm, and
We have a ton of forums you might want to check out for support - the 20-somethings (for those in that age range), or perhaps the "Featherweights" forum, since you're starting out relatively close to your goal. We also have forums by eating plan - what are you planning on doing? We have Calorie Counters, South Beach, Low Carb, Weight Watchers, and other forums geared toward specific programs.
Why do you say that you've had trouble "sticking with" plans in the past? There are a few pitfalls that many members struggle with. First, it can be very hard to avoid being "all or nothing" about weight loss. Either you're going full-tilt and doing everything "right", or you're in your old habits that aren't getting you where you want to go. Especially when you're busy, even more now, in the holidays, you may want to think about making smaller changes that you can stick with for the rest of your life, rather than falling into the "be perfect for 3 weeks, slip up, fall completely off wagon, repeat a month later" cycle.
And if you do have a slip up (EVERYONE does), the best advice I can give is to just get back on track ASAP. After all, one high-calorie meal or junk-food filled day doesn't make or break you if the majority of the time, you're eating healthfully and exercising. But one bad day, if causes you to say "well, I can't stick to this, so forget it!" and give up for a month...well, that'll delay you getting to your goals.
Another common barrier to staying on plan - plans that are hard to stick to because they are drastic and unsustainable. Try to make sure that you're asking reasonable things of yourself. I have see SO MANY folks come in, say "I'm going to eat 1000 calories a day and exercise for two hours with no rest days", do wonderfully for a week or a month, and then burn out and disappear. So if you've had trouble sticking with a plan in the past, you might want to think about ways you can change your lifestyle that won't burn you out after a few weeks.
Anyway, that's lots to think about. Look around, find a spot or many, and keep posting. I can't wait to get to know you better!