Drag your carcass to the mirror. Don't judge yourself for that spot or blemish. But look yourself in the eye and tell that magnificent bastard in the mirror, that they're alright, they're good enough, whether or not they do this task they're still a good person...
And if that fails do what we always do: Wait for the adrenaline rush to kick in and half ass the task in a 10th the time.
You were born this way and it is not your fault. But you can achieve great things nonetheless if you now choose to get going. So take a deep breath, stand up and do one small thing.
Focus on the little first step. Its easy. Just this one. Don’t even think about it. Just jump in head first.