No matter how much or how well I practice guitar, I ALWAYS mess up when filming it, help!?

I know perfect practice, and the quality of practice, I practice very well, and a long amount of time but when I go to film it, I f*ck up so much and I'm not kidding it takes like 45+ mins to get a 2 min song done, been playin 4 years and I'm good...except when I record