Quite simple really: You've only known her for a week and have never met her in person. Mate, this is infatuation - not love.
It's also kind of creepy that you want to take care of her: she's not a child and you're not her father. And if she is actually so immature that she needs taking care of, then it shows that she's a poor choice for a partner.
Time to give yourself a reality check.
I'm assuming that you're doing this online stuff because you're lonely? Time to start getting involved locally and meet new people.
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.