Do i have a case for slander/libel and/or defamation?

an x has told many people that i've beat her, forced her to leave her family, forced myself on her, and cheated on her with someone whom I'm now seeing. Of course i didn't do any of those things. The problem I have with this, other than the fact that its untrue is that I'm a contracted cadet on scholarship with Air Force and i'm told if this accusation was to get out to the wrong people I could supposedly lose my contract/scholarship. However, I haven't been the recipient of any damages done but i am afraid that if i don't do something. I could get in trouble for things I would never ever do. So what can be done?