I need to end my essay. I already mentioned what causes it, what it is, and how it is cured but I still need more.(About hippopotomonstrosesquipedaliophobia)
Your question calls for an "end" to your essay, but then suggests that you need "more." Be careful. A conclusion is different from another body paragraph. If you need to introduce a completely new sub-topic, you are simply adding additional information and will also need a separate conclusion. From the sound of the points you have covered, your essay seems to be thorough. If it is for lack of enough words/pages to meet a requirement, at this point, you have a couple of options.
The first option is to go back and look for places to include additional examples and elaboration to the body paragraphs you have already written. Another idea is to add another subtopic that is different from those you have. You talk about "cures" but what about complications? What is life like for those who live with this disease? Is there anyone famous who has suffered from this disease that you could talk about as a special interest section?
When you are ready to fully end your essay, you will sum up the main points you have made (essentially restating your thesis in a slightly different way) and leave the audience with something to think about. See the link below for some general advice about conclusions.