Completamente capisco. (hopefully my Italian is correct!)

I've been having this problem for months now. It was extremely frustrating and still is. I can't look at anything I write now because it just looks like garbage. Well, compared to my old work.
In any case perhaps you should take some time off. Unless you really don't want to but if you keep at it - most likely your frustration will build and then you can't focus on what you want to write because you think it'll be bad. Or something like that. Sorry if that wasn't helpful.

E questa situazione la odio perchè voglio tirare giù qualcosa ma non viene fuori niente e se prima ero bravina, o riuscivo a scrivere qualcosa di decente, ho paura che se continua così la perderò. This was my fear. I realized that if I really feel like a writer on the inside, it'll always be there. Non sono invincible - though I wish I was (in terms of writing). At least get your ideas down, if they still come you've still got it in you. Words will follow the ideas eventually -en l'italiano or in english.