I am a green belt. I don't know too much about belts in taekwondo, and whether it differs unedrneath separate boards, so I am the third belt you're given under the board WRSA (it goes white, yellow, green etc). As a green belt, I am now allowed to spar more frequently; I now spar (usually) almost every session, and there are 2 sessions each week. I have experience in others arts, including JJJ and Boxing and Capoeira. I am not profecient in any of them, and I quit boxing a while ago because of issues with my coach. I am around the same area (belt) for all of them, but my boxing has helped me a lot to be better in sparring than the usual for a green belt.
However, recently a new person has joined who has kept his 3rd rank black belt in TKD (he was under the same board) and is training to be an assistant instructor. He participates in sparring along with the other black belts, and because I am not a junior (13 or below) I spar against black belts too. Usually, I hold my ground well enough to land a couple of good shots and in some cases dominate the fight (not trying to brag). However, all of the black belts I've sparred up until now in the club were in first rank; they are nothing compared to him!
Now, my fighting stance is the Philly Shell, except I stand a bit more sideways so I'm in a better position ot kick and I'm a smaller target.
I move around. A lot. This is mostly because, of me suffering my first knockout in boxing a while back, trying to block a hook from someone much bigger and stronger than me. The fear of this also causes me a lot of problems with agression and offense in a fight (or lackthereof), me not being able to get myself to punch with my back hand for fear of being too exposed, and whenever I dodge, it's almost always backwards.
Back to new guy, I cannot touch him whatsoever; even if I try to get close, he manages to kick me incredibly hard considering it should be harder for him to use his legs when I'm all up in there, and he also creates and maintains his distance super well. Moreover, he feints his kicks so much and they're so damn quick. He doesn't use his hands at all, and doesn't ever punch.
I have a lot of trouble being offensive against my normal sparring opponents as it is (though I've been overcoming it slowly and made some progress last week) but against the new guy, who is also bigger, faster and older, I simply can't defend or attack. Especially with my bad dodging backwards habit. He punishes me brutally with axe kicks to the head. He is very agressive, arrogant and annoying, but I can't really say anything about it.
How do I overcome these problems and fears? What do I do? Please help. Thanks.