Regretted of fooling around

I wanted to say this for a very long time already, I'm regretted of fooling around.

There was a time when I did a lot of fooling around or flirting with girls, and I used to say something which let them think that I actually like them. But actually I never. There were times when people actually thought I like them, and I didn't care. I just like to play with them by flirting.

Now I'm extremely regretted, because there is one girl whom I think she thinks I like her. And it is not alright, because we are friend, and each time when I speak with her, her reply is so weird!

I'm quite speechless, lol.