What makes you slow and what makes you have a hard time moving is you want to win badly. You want to win badly to the point where worrying, panicking, being impatient is getting the best of you. You want to win so badly but you play not to lose. You are so scared to lose that is why you are not executing the right way. You're struggling, you are having a hard time. You are not giving yourself the freedom to become loose, effortless and express yourself to the fullest, in other words... you are not enjoying what is going on. You keep on pushing and making things difficult even though you don't need to do it.
One way to free yourself is to accept that you've already lost. Accept that you're not going to make it anymore but still take actions, still give your best. It's just like tricking your mind, you pretend to be giving up but the truth is you're still fighting, the only difference is... you're not scared to lose anymore because you already accepted defeat.
Look at an athlete who wants to become an MVP so bad, he is always pressured. He wants to be in control, he is feeling the heavy chip on his shoulders. He is so defensive and he wants to prove himself to others. The moment he hears someone saying that there is a more deserving player than him... he will get mad, he is bleeding for his case, he wants to shout to the world that he is the most deserving. The result is... he lost the MVP not because he is not deserving, he lost it because he loses control of himself. He focus on what he can't control that is why he forget to do the right things. He forget that there are lots of things that he can control that will make him very close of winning the MVP.
If you are struggling badly in something and you wanted to take control... you must learn to let go. Let it go and it will come back. You have to release the pressure so you can make things right. Accept that you can't win so you will have an easier time for moving and taking actions. It is like you are shifting into a "nothing to lose" mode. Just move and be yourself and everything will become easier and faster.