I would recommend learning Baroque fingering. To quote the FAQ area of the American Recorder Society website:
“Avoid the German-fingered ones [recorders]; Baroque/English fingering is now more common than this older system. While German fingerings may seem easier at first, a novice player using them will soon experience tuning problems not associated with English fingerings.”
I’d advise getting yourself a good plastic Yamaha or Aulos recorder and starting over again (sorry). You HAVE to stop using that German fingering!! (IMHO). Baroque isn’t all that much more difficult. As I understand it, German was developed to make it easier for children to learn (no “cross-fingerings”). ‘Nuf said…