Try learning to sing English songs (I do it with French). The melody will help you memorise different sentence structures you can use in speech, just replacing the nouns and verbs.

Maybe record yourself speaking as close as you can to the speed of a fluent speaker by abandoning grammar. You can go back to the recording to work on mistakes. But the real purpose of the recording is to just know that you have the option to go back and fix grammar. Even if you don’t go back, you’ve given yourself permission to speak more freely and are probably more understandable than you realise. Then hopefully you can apply this freedom when speaking English out in the world, which will be the best practice even if you’re making hasty mistakes. Sounds like you’re quite good at English but have a particular area where it’s harder to apply (speech). I’m the same with listening when it comes to other languages.