I've been working on CW for about 4 months now using LCWO and can comfortably copy at 12 WPM, but I'm completely stuck. Every time I try 15 WPM my brain just freezes up and I miss entire words. I'm using the Koch method with 20 WPM character speed and gradually reducing spacing.

Should I stick with more practice at 12 WPM or push through the discomfort? Also considering joining CW Academy but not sure if I'm ready. Any suggestions from those who've been through this?

Brain freeze when getting behind is totally normal! Try the Farnsworth method - keep characters at full speed but extend spacing between them, then gradually reduce. Don't get stuck on that one missed character.

CWops CW Academy is perfect for your level - no cost and they specialize in getting through exactly these plateaus. I found that keying practice helped my brain learn CW better than just listening - try sending the same practice material you're copying.

I hit the same wall! Try SOTA or POTA chasing - the exchanges are simple and operators are patient with beginners. Send QRS or just '?' if you need them to slow down. Real QSOs helped me more than any practice software.