A huge parasitic humanoid attached itself to my head when I was very young, and I want to be free of it. What?

can I do to get rid of it. I believe that because it is enbering my life, I should have it sliced off. Of course, it will die if that happens, but why should I have to suffer in the mean time? The problem is that there are these groups of pro-parasite people who think that this parasite has the right to live, even though it has caused me nothing but problems, and I didn't ask for it to attach itself to me, it just happened. What should I do about it?