Another tip for future grave situations: If there are no sharp turns, ride in the highest gear possible, keep the rpm around 3k and don't put around 10mph, raise it to rather 15. Gonna be a smoother ride. If you need to brake, do it with the rear brake only and some engine braking. It's gonna feel like the gravel is pushing with the bike, like it won't brake much at all.
I've done gravel around 100km within the 50 000km I did so far.
Sand is another thing. If riding up and downhill like in the woods when going to a camp ground, make sure you don't have to stop uphill and keep the inertia going without having to use much throttle.
And when nervous, put all your tension into clamping the knees on the tank. And if you feel good about riding on gravel, play around with the front brake. Simulated a washing out front but I could stay up since the thick gravel was giving in, allowing the bike to compensate. Not saying slam on the brake or hold it while you notice the evil coming up.
I just use bad riding conditions to practice worst case scenarios. Rain is fun to for locking the rear tire on a straight line when rolling towards a red light.
BTW, don't worry about cosmetics. No one yet came up to me and told me in my face why I let that happen.

Never mind the missing tank and the self made gas bottle taped to the airbox. Just the best side view of the scraped right side.