It is important to remember, having an accent is normal. You can live in the country for decades and still have an accent. It is however equally important that you pay attention to the intonation of a language, which syllables to stress, etc. German obviously has sounds that the English language does not but it is quite easy to remember them because in German, you say it how you see it, so to speak. Whenever you learn new vocabulary, write the pronounciation next to it, say it out loud and try to say it in a sentence as well. Watch as many German TV shows, films and news programmes and videos as you can - this way, the sound of native German starts to sound natural in your brain.