I'm getting so depressed, anxious all the time, scared for the future and trying to keep my employer happy and care for the dc.
Mental health just doesn't seem to matter to anyone.
What do you normally do, (e.g. pre-covid) to ensure your mental health stays good?
I have always made time for friends, exercised unless injured, eaten plenty of fruit and veg, spent time outside, made time for myself. I've made it a point to notice if I was getting reluctant to do things (like see friends/go out/make myself look presentable) and put effort into countering that immediately. I note if I start to increase my drinking and clamp down straight away. These are my weak spots so it's what I concentrate on. I did get depressed after having kids because I didn't have the same freedom to see other adults and I slept really badly, so I made an effort to change my situation, enrolling in an online degree to give me a non-baby focus while I waited for changes in our family life that I'd pushed for to come into place.
Now, during covid, those practices hold me up pretty well. I have to rearrange things to ensure I can enjoy nature and talk with adult friends because our normal way of doing things is disrupted, but I have zoom chats with friends, we meet, now, for socially distanced coffee outside in the park. I noticed I had started drinking more so now only drink on weekends. I worried a lot about getting CV at first, so I made myself think of other things everytime I started. I also started discussing how our kids could cope if both DH and I were knocked out by it and put plans in place so I didn't need to worry about the big thing I actually could control.
My point is that a lot of mental health isn't a matter of rolling along and everything is fine and then suddenly, for no apparent reason, you become unwell. It does happen, of course, especially if you undergo trauma, but you can build resilience and make poor mental health much less likely.
Like physical fitness, you need to incorporate good practice into your day to day life, not just wait for something to go wrong before you consider it. Keeping up relationships, spending time outside near greenery, exercising, eating well, not drinking (or indulging in other drugs) too much, getting good sleep, not indulging irrational fears and anxiety when they first start, are all steps that are good for your mental health. The key I've found is to notice early before things become a problem and jump on them right at the start, not indulging them at all. Making yourself go to things you ought to when you first start to get reluctant, cutting back when you notice the urge to over indulge. Shaking things up before the bad habits become ingrained and harder to break. I don't mean if this happens once - there's nothing wrong with ducking out of something once, or over-indulging every now and then - but if the next time you feel the same urge, then clamp down.
Things like meditating or a hobby are other practices that seem to be protective. An activity that takes your mind away from the worries you might otherwise indulge in. A hobby where you spend the whole time chatting with a friend about your worries is unlikely to be much use.
It is harder with young kids because you can't always find time to get a bit of space or to talk with other adults and that's really waring. But it's not impossible to look for the joy in the moment, knowing that this phase will pass and things will change. To make yourself take them to the park/woods/whereever when you do have time. And to lower your expectations for what childcare looks like when you need to work (or even when you need a little time to yourself).