The thing that occurs to me from time to time is starting to read something in English and not noticing that it was in English until after having read several paragraphs. As I said, I'm so used to dealing with written English, but when it comes to speak I'm really in trouble
That's a big step.
I suggest you try one thing: when you are alone, or not speaking with someone, try to think in English all the time without translating. The more your mind organises to think in English, the closest you are to having fluency in spoken speech, although it will take time.
I remember that when I was 16 I went to the UK with a grant. I had an A+ so I guess I had some kind of advantage over the others, but even though I felt confident I still found a lot of problems when I tried to speak (probably because I wasn't very accustomed to the phonemes I should use since English teaching is more aimed at writing/listening than speaking).
There's nothing more frustrating than when you know how to say something but you seem to be stopping all the time when you want to speak although it sounds perfectly fluent in your mind.
Now, a couple of years later, my English isn't still perfect but I've noticed an important increase in fluency because of self-teaching (songs, series, films, books in original version, conversation with university lecturers and erasmus students). There's still a long way to go, but this kind of immersion has helped me with the most important thing: feeling familiar when it comes to utter messages in English while at the same time I've gained some approach to what real-life English is although from what I write, many people will know I'm not a native and needless to say when I speak
although they all understand my "Zombiekish" accent.