I commented my answer to a question, but now I realized how I can answer properly. How do I go back and change the comment so its an answer?

If you posted a Comment under an Answer you can Delete it by clicking on the X Button next to your Comment to Delete it

To Answer the Question on the Question you should see a Add your Answer Box Click on it to Open it type your Answer in and Click Submit

Well, I believe you can delete a comment, and just write an answer instead. Or even if you can't, just write an answer anyway.

To comment you would post a comment below someone else's answer. Comments cannot be edited, just deleted or additional comments added.

To edit an answer you posted earlier, click on the question you responded to, find your answer, click "Edit" and you can change your answer as long as the original poster has not selected a Best Answer yet. Once BA has been chosen, you cannot edit your answer.

Just click edit under the answer (if the BA has not been picked).