Try going back to the 7C. It is ok to try and sound like the players you admire, but I am sure you realize that a 3C feels different to every player. Honestly, pick what works for you. What does "work for you" mean? A mouth piece that allows the process of making music easier on the instrument while allowing you to sound like you. If the 3C is making you work too hard, put this train in reverse and go back to the 7C. Maybe even try a 5C or a 10 1/2C. You never know.
I have been playing a 1C configuration, or very close to that, for twenty years. RECENTLY I played a friend's 3C just to see what it felt like. I was pleasantly surprised that it didn't feel much smaller than what I am using. At this point in my life, a 3C could be in my future before too long, but not yet. So you see, it doesn't hurt to experiment, but if you are having problems like this, the 3C doesn't sound like it is agreeing with you.