Thank you for writing this apology post and owning up to your mistake. Nobody is perfect and everyone makes mistakes every now and then. I harbor no ill will toward you personally and believe everyone should have a second chance. It seems you've learned your lesson from this experience. So as others have said, let's all move on and I trust this won't happen again.

In the future, if you do want to quote a sentence or two from some other source, simply make it clear that it's not your own work and give credit to the source, like this:

According to this article on Wikipedia,

blah blah blah blah

Using mark up tags like > is a great way to make it clear you are using text from another source.