Something similar happened to me a few months ago and I couldn’t shake it. I could heal myself of almost anything and here I was, stuck with someone else’s issue.
It turns out that it’s my willingness to take on other people’s burdens (or sympathy vs empathy) that made me needlessly take this on. It was a wonderful lesson for me. By releasing that belief/tendency it got rid of the ailment.
I have no idea if that is applicable to you but if so, you could use the ego dissolution exercise. I personally used the Freedom Course which is free at www.alchemyofgris.com (you can find more information here on the forum)