I walked ~0.5 miles down an electrified train track in south-east England. In retrospect, what were the risks?

I missed the stop at my hometown at about 12:15am and didn't know my way around the roads and my mobile phone was dead, so I followed the rail track back from the next stop, thinking I was less likely to get lost finding my way home. After about half a mile I jumped a fence and followed the motorway that I knew led into town. It was pitch black all the way and I could barely see bar the moonlight and far-off motorway light pollution.

Facts:

No trains were scheduled to run on the 3 mile stretch from 1am to about 5am, although I now appreciate the possibility of freight trains running me over.

It was two tracks, side by side.

Third electrical rails were on the far left and far right (left of left track and right of right track).

Had a train came, there was about 3-5m of clearance either side of the tracks ending in fencing that I could have ducked into.

I walked in between the two rails for the majority of the distance, except on one occasion where I crossed the leftmost electrical rail to try and reach the motorway, but slid into a shallow ditch and turned back over the electrical rail again and onto the tracks to continue walking.

I stepped over the electrical tracks about 4 times to get about.

In retrospect this was an insanely risky and stupid thing to do, but I'm curious exactly what fate I have tempted? What could have gone wrong? How lucky am I to be alive? It's a bizarre and quite disturbing thought but my morbid curiosity has the better of me if only to teach myself to never do something like that ever again.
Additional Details
If I had tripped or otherwise touched the live rails, would I have died?

Are the rails in the south-east top, side or bottom-charged (done a bit of reading on the rails)?