hi,
i'm a little younger than you, and like 2 inches taller maybe. but i have a really small frame and was always between 108-109. so when i got my first full time job when i was 20 and started gaining weight, i was shocked, but didn't worry too much because i was only a size 3. no big deal, right? but i kept eating fast food on my lunch breaks and i ended up weighing almost 140 pounds when i was 23. i was so sad! i tried going to the gym, but it didn't help.
i'm 25 now, and last summer i discovered green tea! i started drinking green tea without sugar or honey throughout the day. and then i discovered these pills called Green Tea Fat Burner pills. i actually bought them at Wal-Mart for about $10. i started taking those twice a day, exercised a couple of times a week, and stopped eating fast food. i got down to 124, which was good for me! then i cut out sweets and junk food, substituting chips for fat-free pringles (which taste great and if you like chips they come in bbq, sour cream and onion, and jalapeno!) and pretty much went on a low-fat diet. i reduced my fat intake, and although it sounds obsessive, i started reading the labels of the foods i ate before just digging in. from July to September, i lost another 8 pounds. since then, i have lost 8 or 9 pounds, give or take. so today i weigh 107 pounds (sounds little, i know! but i had my wisdom teeth pulled and can't eat much so i lost a pound). but i have a really small frame, as i said, so i don't look anorexic or anything. its all about discipline, honestly. my boyfriend was very motivating, telling me he liked me the way i was, but noticed my weight loss and praised me for it. he helped me workout in the gym, and eventually my metabolism became so fast i burn up any junk food i eat! i still steer clear of candy and regular potato ships, fried foods and fast food, but once in a while i treat myself to a burger or pizza or something. can't give up EVERYTHING!
so try to green tea. just make it up in the morning or at night before going to bed, put it in the fridge so its chilled, put it in a water bottle and sip from it throughout the day. take two of the green tea fat burner pills in the morning with breakfast and two in the afternoon/evening with lunch/dinner. and make sure you EAT A GOOD BREAKFAST! that is the most important thing. fruit, whole grains, proteins, eat your carbs in the morning. not anything fattening. it will start your metabolism so your body can metabolize everything else you eat the rest of the day. cardio also increases your metabolism, so whether you go to the gym or workout around the house, 30-45 minutes a day is ideal when you are trying to increase your metabolism!
i know this was a long reply! sorry! but i hope this helped. anything else you want to know, feel free to ask me!