Avery sorry to hear that...
as far as the rev limiter, just like the previous guy said... The clutch is the middle man between the engine and the transmission. The revlimiter only work for you during acceleration so you can't reach higher RPM's. But when you are already cruising at 100 MPH and you downshift to 2nd, the wheels contacting the ground will transmit all the torque right back to your engine.
The problem could be:
Bent Valves / Damaged Springs
Damaged Pistons
CAM / Rocker system
Connecting Rods (less likely)
Worn out Clutch (burning)
Damaged 2nd Main Gear and Counter 2nd Gear (less likely)
Other transmission problems (less likely)
I don't know what to tell you, did you hit the clutch before the engine Red Lined?
Again very sorry
