Insomnia; not funny any more

For about 5 - 6 weeks now, I have been waking up between 3am and 4am and been completely unable to get back to sleep. I'd get up and do something useful, but I haven't the energy.

It's starting to affect my ability to function now, which really isn't funny. Forgetting where speed limits change on roads I'm very familiar with, not having the motivation to do anything of any use, stupid oversights that risk my boy's safety. And there's no discernible reason for it.

All the sleep-related solutions that I know seem to relate to the actual getting to sleep in the first place; hot milky drinks, relaxing baths, no caffeine, etc. Dr. Internet does not seem to have the answer for when you have no problem dropping off, but can't stay there for long enough to cope with the following day. Drinking too much gin and staying up too late used to help, but it's hardly an appropriate long-term solution.

It's going to be another wall-breathing day, wish me luck.