I am assuming you are the same "anonymous" who wrote about breaking up with your boyfriend. Either way my answer is still the same.....
If you think you made a mistake and made the wrong choice remember this..... "though you can not erase the past, you can always change your future." Use what you learned and make it into something great. If that means getting back together and being stronger then ever so be it. If it means continuing on and learning from your mistake so you don't repeat it in your next relationship then so be it. You have the power to change your future!!! :0)