One of the hardest things in life is moving on from a failed relationship. This is so because we feel like our ego has been bruised and our self-confidence often times plummets. And this is ok. We are allowed to feel hurt from our past relationship. But remember, it's only a bruise. It will heal with time. What we need to do is learn from our experiences and move on. It is possible to love more than one person, and in this case, it is likely that you will always have a special place in your heart for your ex, but it's important to keep the situation in perspective and not allow it to ruin your future relationships/opportunities.
The best thing you can do for yourself now is do go out and meet new people and experience new things. I'm not saying jump into another relationship (as everyone needs time to heal) but I would allow yourself the freedom to have some fun in the process and learn new things about yourself.