Especially for @Claudia_Beryan, but for every perfectionist out there:
Think: What do you want to be perfect at. If you have to be perfect in the moment, every moment, in every detail, then you are going to struggle at any new skill, because that's not how learning works.
So open out your perspective a little, and understand: That little voice that says "that was wrong - you're stupid", or whatever negative message your need for perfection gives you; that little voice can help you, but it needs training. Think to yourself, what is the result that you want at the end of the process? In this case, it's being able to speak and understand Welsh, to communicate effectively and maybe, to have people say "wow - you are good".
So, train that little voice. When you are following the process - which needs you to make mistakes, which needs you to push yourself beyond what you know, what you are comfortable with - then say to your little voice "Yes! I'm pushing myself. I'm beyond my comfort zone. I'm learning."
And when you are comfortable, use your little voice to say "wow, look at what I have already learnt. I need to learn more!"
Because perfection is getting to your absolute potential, and you won't do that without getting a whole load of things wrong on the way. Perfection is getting to the brick wall, the absolute limit, and then just pushing on that little bit. Perfection is accepting where you are, and being able to move on from there, accepting that you are not perfect at something yet, and putting in the work to go from where you are to where you want to be.
To be a perfect learner, in any skill, not just language learning, is to be patient with yourself, and totally, strictly dismissive of excuses and impatiences. From my own experience, that is impossible, but if you're aiming for it, then it helps you to get the perspective to see the excuses and especially the impatience, for what they are: the things that are holding you back!
And if you have that little voice that says "what if people laugh at me / take offence that I make so many mistakes"? Then remember, most people won't push themselves through the barriers. By being willing to take the hits, the falls, and getting up again and agin, you'll be way ahead of most other people. Most people will accuse you of genius, and being "a natural", and mistake your hard work for luck. And the best of them will find you inspiring, and want to follow you. And there's no "wow you're good" better than that!
As a sometimes-reformed perfectionist who knows an awful lot about not doing stuff because it may not be perfect, I'll leave you with a video that I always refer to when I'm concentrating on the wrong kind of perfection: https://www.youtube.com/watch?v=Bx2nvIViZuY