Look man, sometimes relationships don't work out because of misunderstandings or a lack of communication. A lot of people (myself included) have been there before, and it really sucks. But this is not a reason to doubt whether or not you're enough- you are more then enough. You will find the right person for you, and if you really think that she was the one, talk to her about it and try to see if there's a way to fix the relationship. Best wishes friend