Hey Determined93, cut yourself some slack - that's a solid loss. Have you considered reducing your dose a bit to see if that helps with the nausea and sleeplessness? 40mgs is a lot. Otherwise, I can highly recommend dimming all the lights after the kids have gone to bed and running yourself a luxurious magnesium bath - which will also help with the muscle pain.
Pushing yourself involves challenging your body and mind to work past your comfort zone. You should feel fatigued, but you should be able to carry on with the rest of your day without being too drained to accomplish daily tasks. If you find that you’re unable to accomplish, or you're disinterested in normal activities like work and socialising with friends after your workouts, that may be a sign that you're pushing too hard.
Not being able to catch your breath for a short time is OK, assuming you just did an intense short workout, but not being able to catch your breath for a few minutes after you stop is definitely a sign that something is off.
Your heart rate is also a good indicator that you might be pushing it too much You can check your resting heart rate (i.e. your heart rate when you’re not working out), check it right after the workout and then check your heart rate again when you get up in the morning. If it starts to go up in the morning, then you are most likely overtraining and your body isn’t recovering well.
While it’s fine to be sore here and there (and likely to happen when you push yourself - especially if you are going from nothing to something), having soreness beyond normal—meaning, you never seem to have a day when you aren’t sore—is a bad sign. It could mean that you are pushing yourself so hard repeatedly that your body isn’t able to repair itself—and that can lead to injury. Typically, when I start working out, I am sore for the first week and then it goes away once my muscles get the message that 'this is what we're doing now'.
Consistency is key. Results will follow.