There are many tactics - google will get you all of them no doubt - to counter mental health problems. Exercise, eat well, sleep, read, meditate, etc.
The biggest thing for me is to accept my mood, no matter what it is. I may wake up grumpy and that’s ok. As long as I don’t dwell on it I find the mood changes, eventually I realise why I’m grumpy and it’s usually something I can fix or something to ignore.
It is not easy.
Ask your loved ones (be they family or friends) how they are, then ask again to be sure. No-one will admit they are depressed or suffering at first, open the door to them and just listen. Don’t fix.
And take care of you. If you need a day of doing nothing, do so. Try not to let it become the habit.