There are plenty of peeps on here that will give you some advice but I thought I would add my two pence.

Since ive started Taekwondo ive always been actively involved with the competition element. My instructor has always been geared towards that so I guess it was bound to happen that id follow that route!

Anyway, in 05' I had the opportunity to take part in the World Championships. Rounds were 2 x 2min with a 30 second break in between. So quite demanding physically.

You mention that you do put in the rounds, so my suspicion is that you have fallen into the trap of bouncing around for 2 minutes, throwing some techniques etc (hey, we all do that sometimes/and I stand corrected if ive made a guess there!). But if your doing ten rounds and not feeling the benefit in competition then there is something in your training that you need to examine.

A round should be physically demanding and if its training for a bout it should be intense to the point where you are struggling to breathe.

But thats just one of many factors you need to consider. Diet, fighting mentality all play a part in sparring.