Yeah definitely watch the noise levels. Your ears can only handle so much for so long. I took out my subwoofers because I was waking up with ear pain. It was like I had to actively try and "wake" my ears up and I could hear them deafening in the morning shower. There are times when I really miss my system but I know I'm better off without it at the moment. I can also tell I'm slightly more deaf in my right ear and when I talk on the phone I can notice a huge difference. I attribute the deafness in the right ear due to riding with the windows down so it's like the bass is traveling through the center of the car and out the windows from the pressure and dynamics and such. If you take your system out now maybe you can recover. I'd also recommend some Magnesium supplements; there's been evidence saying it can help in protecting your ears. Don't go overboard though because I think too much can have an adverse effect. Magnesium can also help regulate your mood a little, so it's got health benefits of it's own. Just don't get magnesium oxide there's not much absorption and it's cheap. Try to get some cheleated or magnesium oxalate. There are also a few other molecular forms that could be better absorbed but I know cheleated is a pretty solid option.
Another good way to tell if you're ears are going is to listen to some pink floyd over time. I can tell that I can't listen to some of the songs at as low a volume as I used to be able to because I can't hear some of the outer frequencies so I have to turn it up more. It's like I can remember where some of the notes used to be.
Also, don't think that you're immune to ear damage from headphones. Headphones can be a silent killer, and sometimes I can definitely notice that after a workout at the gym i'll get that same deafening effect I used to get from my subwoofers back in the day. Especially with all these in-ear models that you cram into your ear. There comes a point in your life where you have to decide if you want to set yourself up for wearing hearing aids at an earlier age or not. My grandpa is deaf as crap and he never had subwoofers or headphones. He also refuses to wear hearing aids (i prob wouldnt want to either), but it's annoying having a conversation with him because you have to try so hard sometimes to get normal thoughts off, and after you repeat it a few times jokes and witty comments kind of lose their "punch". I find myself having to ask people to repeat stuff to me sometimes, and when that happens you can definitely tell you lose a certain "fullness" to the conversation.
Now I just save my ears for nights at the clubs or for festival/shows. Remember hearing damage is kind of exponential, in that once they're damaged they're a lot easier to further damage. Your girlfriend will also think it's a good step in the right direction. Girls that are really into bass and stuff may have a Histrionic personality disorder. I'm sure some of us here at caraudio also suffer from the disorder as well. I for one have done some research on a few of these disorders and it's kind of scary when you read about some of them (there are a few others besides histrionic that I think could be contributing to some of my behaviors). I've been trying to do some serious psychoanalysis on myself lately and engage in some psychological conditioning to try and relearn some of my more "natural" habits.
I'm sitting in my chair "clicking" my ear drums right now wishing I had taken my woofers out a little sooner. If I ever put bass back in my car it's going to be smaller than a 12''.