Train commuting vs cycling, which is more dangerous?

I'm still not allowed to cycle... in case I fall off. This means that this morning I was yet again braving the train commute. After noticing I seem to be jostled often, this morning I decided to count the hits.

My right forearm was hit 10 times by people's bags or elbows, and that's only counting the ones that hurt. I also nearly got shoved off the train at Ealing Broadway and would have fallen flat on my face and probably thrown my arm out to catch myself.

The theory that it is somehow 'safer' for me to be doing this every morning instead of cycling is becoming more and more questionable. Dogs and small children are continually at my feet attempting to trip me up, I am shoved from behind as I step off high trains onto low platforms by people anxious to get to work, people with ridiculously large bags with hard edges swing them into me as they plough through the crowds.

I haven't even factored in the higher risk of obesity and heart disease caused by sitting on your arse on a train instead of cycling.

Oh God, I'm doomed!

PS: Am still waiting for my key to a Boris bike....