I don't think college was your biggest mistake. College is just an experience, and unfortunately sometimes it doesn't work out for some, you in particular. Your biggest mistake was not to quit when it was very clear that it didn't work out for you. Instead of quitting, you let that bad experience chew you up and spit you out.

You hit bottom.

The better story to tell here, IMO, is that when you hit bottom somehow you found inspirations to bounce back and became successful. This is really the story you are telling, and it's a good story.