Its not an engagement unless ya gotta ring and a date

Do not get married until you have spoken to your ex. You have unresolved feelings. He told you he wished you two had never broken up? You need to speak to him. What if he is the one you should be with?

Just accept that you may have made a mistake. Then move on.

i dont think so

You're not horrible but you need to figure out what you want. If your ex doesn't want to get back together that simplifies things and you get to focus on whether or not you want to marry your fiancé. If you don't think you'll be happy with him, don't waste his time. But be honest with yourself, so you don't do anything you'll regret with him. We don't always get "do-overs" in this life. Sometimes you make a decision, you're stuck with it.