Learning is messy. Mistakes are an extremely important part of it, in fact mistakes can be seen as a part of the definition of learning: if you don’t make any mistakes: You are not learning.
Why? Because if you can already do something, then you are not learning anything new. In order to add to your skills, you have to do new things, new things you can not yet do. So in order to grow, you have to mess up.
I see music students struggle with this every day. Adults or kids, when people do something they naturally want to do it right. But as I've shown above, that's not gonna happen. When you learn music you are doing something new, you will mess up. And this is not true only for beginners, any musician trying a new thing, experimenting, growing will make mistakes with it. That's true for me, for Steve Vai, for Beyonce, for YoYo Ma. You don't see professionals mess up; that's because we are performers and you normally only see us performing. You do not see us practicing, rehearsing, composing, working things out. Sure it's a different level. Doesn't matter, it's the same process.
So ease up on yaself.
Pay attention – if you make a mistake, you have to hear/see/feel it.
Evaluate – if something went wrong, what/why/how, that's what you need to know.
Play it again – adjust whatever you think needs it and try again.
Repeat – and never give up
Love your mess. It'll make you better.