want to go back to how it used to be

ok so 8 months ago, me and my gf got together. In the beginning she was so in love with me and obsessed with me and wanted me and i loved it. but then i started to get really jealous and accuse her of doing things with her guy friends. Then during the summer she went away for two months so we had minimal contact and i got really mean and hurt her a lot. Then when she got back we worked out the issues and were doing good until i started getting jealous again and for the first time ever, she told me that we should end. She said she still loved me but she can't deal with the pain that i put her through. i want things to go back to how they used to be. oh and she also told me that I'm too needy and obsessed with her. and she just doesn't make time for me anymore like she used to? What should i do to ensure that she is completely loyal to me and to make her want me like she used to. We used to text 24/7 and now not even close. We also used to talk for an hour everyday and 2 hours on the weekends cuz she always wanted me but now no more!! help please.