Me [27 M] with my Fiance [20 F] 1 Year, Canceling marriage because of an online game!

We both have everything in common and everything is really going smoothly, however before i met her i was playing an online game really heavily called Dota i have more than 6000 hours and after we started it, i was still playing and i was trying to play less but my effort wasn't so much and i reduce a day then a day i don't.

So this affected us heavily and my attention to her was less than i should, and we broke up now i really regret it and woke up and saw what was the reasons (late i know but better than never) so i stopped playing for real (not even 1 second) and changed my life completely in only 1 month, and now i want to fix everything, what should i do?

Thanks

tl;dr: Marriage messed up because of a game, need advise how to fix it (after i fixed my self)!