weight help.

Im 20 years old and have battled being over weight all my life. I just dont know what to do anymore I do not see how others see me i feel as tho I am a skinny person in a fat persons body , my weight has yo yod alot and i have been consumed in school and tired alot and havent been eating well and all the weight that i had lost i have gained back and some i now weigh 300 pounds and i feel like a failure and i jist dont know what to do anymore . i am so lost.