sorry, but there's a lot of victims of society here. People used to wander around by themselves all the time for months on end with no bad things happening to them. Really, you'll be able to go on a thousand night rides by yourself with no ill effects. Even if you fall off, you'll scrape yourself a bit, oh no. Cripes, if it gets really bad, you'll maybe break a rib, or an arm even. YOU'RE NOT IN THE **** ANTARCTIC, YOU'RE IN BARNSELY, OR CLEETHORPES, you're three miles from the nearest macdonalds!
If you've not guessed, I ride solo at night all the time. I don't believe it carries any additional risk than riding alone during the day or going out for a quick pint. No, actually, I'm going to call people's bluff. if I go out for a quick pint I expect the chances of me getting my head kicked in or a glass in my head are slim but are still massively higher than me falling off my bike on a solo night ride and hurting myself to the point where I cannot get myself to civilization so I die.
Take a phone, or for christ's sake, live a little.