I have wrinkles on my forehead ...help?

i'm only 14 ...i didn't have them when i was 10 or 12 they showed up some were between 13 and this year ....i have gained 50 pound the past 3 years and now i am overweight .probably because of my low exercise and pigging out once a month ....what can i do to take them away? if i lose weight will they go away? or will they be there forever? back when i was 12 my jaw line was visible and i has no wrinkles ..but if u look at pictures of me at 13 and right now ...my face is round and i have wrinkle on my forehead ...it makes me look daft ..please help