I am the victim/witness in a DV case against my ex-gf and I got subpoenaed to testify. Can I plead the Fifth based on our rocky relationship history?

I have expressed my wishes to both the defendants attorney and the DA that my desire is the case dismissed/dropped because I still care about her and the event that got her arrested happened in seconds and might have been a mistake. Possible mistake was my senses, such as her using me to balance against a fall as something with violent push or shove because I took something away from her during the altercation. Unfortunately, at the time I did speak to the police and said that my ex-gf caused this scratch that I did not know about until the police pointed it out, but only a month later I realized that the scratch is something I might have done myself as a result of me taking an item away from her. I told this to the defense attorney. Thing is even though she is the defendant and I'm victim, in the past, it could have been me as the defendant and her the victim. Hence the Fifth. I dont want to help the prosecutor by testifying and protect myself since she also is a victim from our past.