Jamal: Yes, I see you have a real mess. The easiest way to fix what you have would be to look at the styles list to see which one is the most populous. In other words, which of the 'manufactured' styles occurs most often in your document in the kind of text in question (not the italics text). Rename the style to something like Body Main. Then select all the text you want to look like that text and apply Body Main to it. Then they will all look alike. Word creates 2 different kinds of styles: character styles and paragraph styles. Look in the styles list to see one called Strong. The Strong style is a character style - meaning that the style attributes are only applied to selected text, not to the entire paragraph. You can create a new character style just to add italics to your text.
Once you have created a style or renamed or modified an existing style in the list, then you can modify its properties to include whatever you like and the text in your document will assume those characteristics immediately.