I was with my Ex for 3 years and We have a 11 month old Daughter, I did a lot of thing that were bad, I didn't cheat or anything I just could not hold a Job and being stupid with Money, I have Changed, But she is not even giving me a chance to prove that I have,

My Question Is, How do I get her Back and how do I get her to notice I have changed

I know what your ex is going through. I was with a guy for five years we were married and we have children together and everything. When I finally broke it off it hurt a lot. I didn't end it because I didn't love him I ended it because when I was going through all the bad stuff with him it started to bring the worst out of me. I tried to hold the relationship together and I looked at everything I did wrong and thought it was all me. Then after a few years I couldn't take it anymore. After feeling disrespected, unappreciated and completely drained from holding the last of the threads in our marriage together I realized that I couldn't change him to be better and that I couldn't trust him. You can be with someone if you don't respect them and you can't be with someone if they don't respect you. It all goes together.
Needless to say we did not get back together. I do see though that he has made a lot of changes in his life now. I respect him for that but I can't turn around and undo all that l have learned in that relationship. I learned a lot about myself and I found a new and stronger me. I didn't need respect from him I needed it from myself. We remain friends though and I still care for him. Its just when I got out of the marriage I came out of it a different person.
Maybe you should just give her some apace and let her slowly see the changes you have made. Im sure she still loves you but you have to realize that she has been through a lot emotionally and those are the hardest wounds to heal. If she doesn't come around you are going to have to except that. It doesn't mean though that you can't have a friendship. Try to be her friend first and earn back that trust. Don't rush her into a relationship and try to fix it. Trust me it will push her farther away. It all takes time. Good luck:o

bananaBean has an EXTREMELY good point

You can try to keep a good relationship with her but there's a pretty good chance that you won't get back together unless you magically patch things up

And if magic doesn't work, the best you can do is learn from the experience, love your daughter, and use the new changed you to your advantage

I'm sorry if my opinion doesn't work for you, best of luck

If you want to win her back, you have to set your life straight first. How can you take care of your girlfriend and your daughter if you can't even take care of yourself.

Spend some time to find a stable job and control your spending habits. You have to show her that you are in control of your life.