Hi, first time poster.

Problem: work stress has for the last several weeks led me to constantly waking up in the middle of the night, often times with a lot of anxiety. This then sometimes keeps me awake the rest of the night. I have no big stress during the day or issues falling asleep. I'm wondering are there particular practices during the day/middle-of night that may help with this. 

Background: I've been meditating for about eight months, typically an hour in the evening mostly just breath meditation. I find it helpful and enjoyable, but obviously my subconscious is still not full on board I often try to just lay in bed and use noting or breath meditation to calm done. This helps a little, but I'm usually so tired/stressed to keep it going or to be effective. I'll be attending my second 10-day course next month, but I'm wondering if there's anything else I should be trying to do that can help me get a good night sleep (other than quit my job hah).

Regular cardio exercise, during the day, like running, riding a bike fast, or swimming often helps. For some reason, outdoor exercise seems to be particularly effective. If you do wake up, counting backward from 100 is surprisingly effective for many people. My wife swears by it and says she almost never gets all the way to zero before drifting off. Also, getting up and having warm milk and something light to eat, like a piece of toast, works well for me. 

Meditation can actually increase stress and overthinking at times, and so it's useful to have ordinary things like diet and exercise in place to keep us on an even keel. 

I find his helpful:
https://ncu9nc.blogspot.com/2020/08/preparing-for-meditation-with.html

It's better to learn it when you are not having a lot of stress so you know what you should be trying to accomplish, but I think it would still be helpful in your situation.

At first just consider it an experiment to see what happens. If you find it helpful you can do it when you get home from work, and/or before bed, and/or if you wake up at night. If you practice you can improve your skill at relaxing which you can use in daily life if you try.

In my own practice I try to maintain the relaxed state as much as possible during the day (I'm retired) so I can notice dukkha arising and fading by the absence and return of the relaxed state.

By itself, being relaxed is incompatible with many types of suffering so it is beneficial to clutivate it. But that is not the main point, the main point is to use it to study dukkha arising and fading. That study reveals how the sense of self (ego) is involved in much suffering, and improving your skill at relaxing (relaxation power) helps improve your ability to interrupt the sequence of dependent origination. When you notice stress just starting to arise you can use your skill at relaxing to stay relaxed without suppressing any thoughts or emotions. I don't know if this can really be perfected 100% but I think for practical purposes that is a logical/reasonable goal.