My advice is to not go along with a 'break'. Especially an indefinite one. How selfish of her!!!
I'd be telling her that i will only accept "in" or "out" and not a half assed relatioinship. Tell her "I'll consider myself single and go and date other girls and whatever else that entails" Tell her that if she decides to give it another try, you'll consider it if you're not seeing anyone else.
Do not let this woman stick you on the back burner till deems herself ready to try again. Showing her that you're not a doormat will gain her respect. Having said that, if she ends things, it just proves that this break was simly her being too gutless to end things decently.
Never regret anything that has happened in your life. It cannot be changed, forgotten or undone. So, take it as a lesson learned and move on.