Heart Broken this is 2 hard

ok, my ex and i had dated for 3 months, i know not really long. anyways, at this point, its only been 4 days, but i can bearly eat and sleep. ill got to bed at 1 am in hopes i will sleep in, but i wake up a 5 am, and cant get back 2 sleep. the reason we broke up (or at least what im told) was b/c shes been upset 4 some unknown reason, and she asked me 4 space, i had a really hard time giving it to her, but it thought i was. any ways i called her one night to talk 4 a little, and it just got into our relationship. the whole point of this is, how do i get her back, this is the hardest thing i have ever been through. im sick of crying, and not sleeping. shes always on my mind, and the stupidest little things, remind me of her. i talked to her 2 days after we broke up and i asked her if she was happier w/ out me, and she said no. i also said "dont it bother u that we're not 2gether" and she said "yeah but theres nothing i can do about it" and i said "u could go back out with me" and she said yeah but its not that easy" i also know her friends were telling her that she had changed since we got together. im not sure if thats why it would be hard or not. i just feel like i need her in my life.