@Xitor I fly analog and don't use GPS or height sensors.
I recommend to "sneak up" on diving, practice getting lined up and oriented up high near some reference structure (that you won't lose your quad on) and be sure to pull up and out early, trying lower and later exits. Also watch for propwash, you want a curved trajectory away at the bottom. If you just level out and floor it, the downward momentum can push the quad into your own dirty air and you can almost completely lose thrust, similar to a plane stall.
TinyWhoops like my Mobula 6 HD can have a hard time just regularly descending without losing lift and yaw control, sloped, spiral, and always forward or curved paths are the same remedy here.