That all sounds very familiar.
Being your own worst critic is good to a point (the really shit artists and artisans are the ones who aren't) but it can be very debilitating. It is much harder to be a perfectionist than it used to be because the [near] perfection of the masters and the ever so high standards of the oh so many experts is so readily available to us and there's just such a vast and ever-growing quantity of it. It's hard to stay motivated against that backdrop.
Being a perfectionist can cause a situation where the chase is better than the catch when it comes to learning. Learning is fun because there's no pressure to get it right first time: mistakes are fine - you learn by them and you know that; you're chasing the prize of getting good at it. But having learnt, then doing it becomes no fun because every little mistake is an imperfection that makes the end product bad/wrong/embarrassing/etc. The trick is, of course, to keep treating it as learning because, of course, we always are.
Also, a great man once said "Nothing, except a battle lost, can be half so melancholy as a battle won". The battle is fun, the aftermath isn't and it's the aftermath you deliver to the audience (with things like writing). Overcoming that relies on being able to enjoy (or at least appreciate) your own work and not take it too seriously: to not look at it as a critic.
These are things you have to break through if you want to do it seriously. I think the upside is that a perfectionist who can break through (because it never completely goes away) will probably then have the grounding to be really proficient.
Having said all that, some things might be best left as a hobby where they are more fun: having creative outlets that you don't take seriously is very important I think. Perhaps you're dodging a bullet by not having to write a tedious article every month
Disclaimer: I haven't overcome any of this myself so I wouldn't take advice on it from me: only when I'm 100.00% sure I know the cure that works for everyone, then I'll get back to you.