Well here goes,

I've been with her for a while now and we've been through so many ups and downs, in the past, when we FIRSt started dating, I hate to say, I've cheated on her a lot, but I've changed and she knows I'm trying my best, I don't think she's gotten over it and I just really want to show her that I'm different and that I really do love her... how do I show it!

And another thing, I admit that she's my everything past advice has told me to put my main priorities first and shouldn't put my love first... I think it's too late for that.is it? If it isn't, how in the world do I change what's done?
Expert advice anytime soon please !

Unfortunately you can't change what has already been done, the best advice I can give you is.. say what you mean, and mean what you say, if you tell her you won't cheat on her again MEAN it. You cannot make her believe you, you have to give her time. It was the same with me and the ex, he cheated,when I found out he gave me his word that he would never do it again,he promised me the world and everything in it,then when I started to trust him again he did it again and again until I told him where to go,I left him, and guess what? Almost 7 years after I left him he is still calling me at 3am asking for me back, even though he knows I have been with someone else for the last 6 years. Be happy with what you have, and if you are happy with what you have,treasure it, as it might be gone tomorrow.

BeYond ConfuSed -_-]Well here goes,

I've been with her for a while now and we've been through so many ups and downs, in the past, when we FIRSt started dating, I hate to say, I've cheated on her a lot,
Cheated a lot? This is a dealbreaker with most people. Your lucky
But I've changed and she knows I'm trying my best, I don't think she's gotten over it and I just really want to show her that I'm different and that I really do love her... how do I show it!
That you can pass over your bad behavior and expect her to just get over it is selfish, very selfish on your part. She may never fully trust you again.
And another thing, I admit that she's my everything past advice has told me to put my main priorities first and shouldn't put my love first... I think it's too late for that.is it? If it isn't, how in the world do I change what's done?
Expert advice anytime soon please !
Set this poor female free and let her have a real life, and you take the time to work on yourself.

Get her a promise ring... and promise you would never do anything like that or anything and you'll always love her and promise you always want to be w. her... find a cute way to give it to her... it doesn't have to be much but it's the thought that counts... work for me and she's been wearing it everyday : )