Can I sue her in civil court if I was kicked out of my apartment that I shared with an ex-girlfriend while I was traveling?

Your question requires an attorney consultation. It is not a simple question that can be answered on this type of forum. There are many factors that would need to be considered and evaluated. I strongly suggest that you contact an experienced landlord/tenant or real estate attorney for a face-to-face consultation and give him/her all of the facts surrounding your situation. (S)he would then be in a better position to analyze your problem and advise you of your options.