Forum Moderator Libel Question

I must first start by saying that this may be considered too trivial to be considered worth your time. So I will be as brief as possible and I apologize if this situation is not worthwhile.

-I am being accused of “lies,” “slander,” “libel,” editing the internet posts of a person and then posting them online.
-This person is the moderator of an internet forum and has accused me of the above actions. This has led to my ban from the forum.
-I have several screenshots of this person’s posts, posts that intended to cause my reputation harm. This person claims that I have edited the pictures to make them look bad and that she has maliciously lied to attack my reputation.
-I have tried to ask, simple, direct questions, to solve the situation like adults, but she continues to maliciously and without justgrounds attack my reputation.
-Therefore I am considering legal action. I apologize if this is not worth your time, and I will gladly provide any more specific information you might want before deciding if my situation is worth an effort.

What can I do.