This thread is great
If you can't stream then you haven't gone through the required physical development to be able to stream.
Streaming is not like aim or reading, you won't just 'get it' eventually, you actually need to work towards it. Fuck that guy who said stream practice maps aren't helpful, they truly, truly are (and worked for me), because they'll push the physical development you need to be able to stream well. Play streams a lot, every day, until it burns. If it burns while you're playing, good. If it burns when you're done playing, bad (you've overdone it). Every day you'll notice an improvement even if it's just being able to have the stamina for one extra note.
Learning to stream well takes a lot of hard work, so if you really want it, work hard. That's it. Start off at your upper limit until you can competently do it. Add 10BPM. Repeat. It gets exponentially harder. Btw, my range is 190-300 so take my advice if you want to be a faster streamer, I guess. Stream control is an entirely different thing.