Bois, there are a lot of people who don't understand that 'not ready' means that you haven't found 'the one' yet. Not understanding the link doesn't mean that they are intending to bullshit you.
Anyway, if you don't want to stay friends (which is entirely your prerogative), it would help if you told her how you feel. She may be under the illusion that a friendship with you is possible. Once you tell her that you're not interested in only friendship, there's a strong chance she'll leave you alone.
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.