Can't control spacing after paragraph

Use Ctrl+Q to remove any direct paragraph formatting which has been applied to selected paragraphs (or to the paragraph that contains the insertion point, if nothing is selected). 

Also, keep in mind that if Spacing After "meets" Spacing Before in the following text paragraph, Word will only apply the larger of the two values (spacing won't be added together). I'm not sure if this could be part of the issue in your document.