I have been with my recent ex on and off for quite some time. Most of the off times were because I was in college and felt like chasing girls and having fun... Ill be honest. We were together for about three years, took a 6 month break, and back together for another 6 months until our recent break up.
The break up was caused by a stupid move on my part. I work as a bartender, and as many male bartenders know, female attention is not uncommon. This one particular time when a girl asked me for my number, Instead of telling her i was not single, I decided to humor her and give her a fake number. As im doing this, my Ex's friend takes a picture of me telling her my "number". This picture is sent to my girlfriend and hell breaks loose.
Even after trying to prove that i did not give my real number, she did not believe me. I mean, the simple action of even pretending to give it is a pretty dick move so i didnt blame her for being pissed. But now she is saying that she cant trust me because that incident brought back all of the trust issues we had before with me chasing other girls.

Now, i KNOW this is not in my favor what-so-ever and may be unfixable. BUT I would like to see what some of you guys would do in order to regain her trust and another chance.

Sure there are "plenty of fish in the sea". But ive dated tons of girls during times we were not together and they all suck so im looking to settle down with this one because i do love the girl. So WHAT would you guys do ?
I tried no contact for a few weeks, and saw her for the first time the other day and as soon as i looked at her she cried. So she is obviously still hurt by what happened, but feels she simply cannot be with me because she feels i will hurt her again.
I know this whole relationship might just be shot, but im willing to try getting her back.

Any advice or methods for this type of situation is greatly appreciated.

Thanks a lot guys.

That story even sounds like bullshit to me and I don't even know you.

A fake number? And this got captured on film and given to her... Anyway, just saying - it sounds like a flaky excuse... is this really what happened? (completely cool if so, I'm objectively stating that I can maybe see why she's had a tough time buying that)...

Seriously just apologize sincerely to her again in person. Tell her you'd never hurt her intentionally and you want her back. Good luck, buddy.