Generally sounds like you’re front heavy on landings. So…
As above really, I’d check your fork pressures, once you’ve set sag right, dial in some compression damping to stop bottoming out.
Next I’d look to turn your brake angle, so they’re almost flat, and horizontal to the floor. If they’re pointing down, you’re going to be pointing down.
Once you’ve done that, you can drop your wrists, so you push through the bars, not down.
Then, drop your heels. Same affect as above, and you’ll lower your centre of gravity.
Shorter stem will help, wider bars won’t. But they’ll make the bike feel less twitchy, 630 is very narrow, very narrow. However, I’ve seen guys riding narrow bars very well indeed.