well i don't think it is self confidence that is making you play bad, the same goes for you a.j.ing.
it think it is fear. you seem confident in your game and you know it is good. however you seem to fear throwing your best game at someone and them walking all over it.
you both sound confident that you know you are good players, so just go and do it. if someone blitzes you then so be it. that is the time to step back and say, "yeh they were better than me". and that is when you go and do your practice and your training and continue to come back until they have to fear you.