@ariz.
I think you are facing resistance in starting of an essay or for that purpose paragraphs. When you have enough knowledge about an essay, even then you little confidence for going to write. The problem is simple you do not know how to start. For that purpose, you must practise writing topical sentences to begin paragraphs of your essay. Topical Sentence is,in fact, a statement which you elaborate or prove in your paragraph. Your paragraph should talk only about the topical sentence.
Study a book named "Writing Talk" about developing your paragraph and the paragraph about introduction. I have forgotten the writer of the book. It is , however, famous book and available in the market.