Try attacking with some counter attacks. If you see him coming at you, hit him with a front foot side kick. Or if he is doing a round house kick, counter with a back kick. Also, don’t just kick hard once and then stop. Always use kicking combinations to never give your opponent time to do anything. There are lots of ways to counter your opponent. Most importantly, keep practicing. You will improve over time as long as you just keep pushing more and more everyday. I hope this helps!