Defo have been and will be going. I love concerts! With my first T, I didn't even use ear protection most of the time (although of course I
would strongly recommend you do, even if you don't have T!) and was just fine. Now with my second T, I use ear protection (mostly strong - at rock concert levels, you'll still be able to hear everything just fine, in fact it might be clearer that way). Always been alright, at both rock concerts and clubs.
That said, be reasonable. Since you have T, you're probably sensitive anyway and will quickly notice if things get too loud and/or unpleasant. As a musician and producer, I can definitely tell you that yes, rooms do make sound louder due to reflection and reverberation. If you're super cautious, just remember you can always go outside and see that you're okay. Other than that, by all means go, relax, have a couple and enjoy yourself! If nothing else it will take your mind off the tinnitus! The tinnitus might get stronger while you're wearing ear protection obviously, but that's no reason for me to not go enjoy the band. Take it from someone who actually GOT his first T at a concert.