I found finally the solution after days of searching and testing, It turns out to be very simple actually.
All i had to do is use a metaphase editor panel, (which has a great toolbar by the way) create a DocxEditorkit and then set the editorkit of the metaphase editor panel's textpane to this DocxEditorKit, although the metamorphose works with HTML text pane, it miraculously worked...
DocxEditorKit DEK=new DocxEditorKit;
MetaphaseEditorPanel MEP=new MetaphaseEditorPanel;
MEP.getHTMLTextPane().setEditorKit(DEK);
//Try and Catch blocks of course to read the file
DEK.read(new FileInputStream(PathToFile), MEP.getHTMLTextPane().getDocument(), 0);
getContentPane.add(MEP, BorderLayout.CENTER);
And that was it... Who thought it would be as simple as this.