I actually don't think there should be a problem with it at this point. You're not run by the same kind of government as you were about 70 years ago. Germany's transition and current place in the world should give you a lot to be proud of and you should be allowed to show it. I'd punch someone for you if they got on your case for it. So, maybe try to not be a sucker to someone who would sympathize with you?Germans simply aren't big on patriotism or national pride, because of our past still, that stuff is hammered into us at school. There is a video out there of Angela Merkel disapprovingly throwing away the German flag at a celebration of her party, meanwhile Trump goes around hugging the American flag, that kinda shows the difference in mindsets.
I don't feel national pride either but for me it's because I think that pride is an emotion that you should feel for something that you've accomplished and nothing else. What have I done to make Germany what it is today, that I should feel proud about? But I do am happy to live in Germany of course.
The main thing that annoys me is when people take every instance of national pride a German might display as signs of someone being a borderline Nazi. I had a date with a chick during the European Championship last summer, who told me she liked going around taking the German flags off of people's cars (which are fairly common during big international sporting events) because how dare people show support for a sports team like that. I nearly rolled my eyes so far back that I was able to see my own brain.