How can I prove my love to my exgf?

Alright, we broke up 9 months ago because I was in a bad situation in my life and I didn't pay enough attention to her and she just told that she doesn't wanna be with me like this anymore. Then she left me and after that I started to miss her and love her more and more day by day. I was like be awake till 6 AM and cry on her pics and old chats.

After 9 months, I am feeling I need her more than anything and anytime in my life. I used to be a creep and I hurt her earlier, and for that I didn't want to disturb her anymore and tried to forgot her, but I can't and I don't want to. I decided to talk to her yesterday, and we talked and she said she doesn't want to be with me anymore and she thinks that I am gonna be like before and she is gonna be hurt. But I really love her now, and I changed myself for good and I just can't live without her anymore. She says you have to move on and forget me but I just can't think of anything and anybody other than her.

I wanted to ask how can I take her attention and try to persuade him and get one more chance from her? She won't give me another chance easily because I used to ruin her chances third times.

I really want her back, I just thought maybe anyone could help me here...

Thanks in advance, best regards.