Create tiny pockets of fun every day. E.g. when you wake up, play a few of your favourite songs from your teenage years as you get breakfast/kids/pets ready.
Wake up 15 mins before others and brew a fresh coffee with frothy milk (just heat in a jug in microwave and beat with a whisk until frothy) Drink it slowly, watching the moon go down or the sun go up or listening to the birds or checking the sky for the day ahead's weather. A bit of tranquillity and nature. If you don't like coffee, tea or herbal tea.
Have a hot bath or shower. If you enjoy it, add bubbles to the bath and light candles or play soft music or read an escapist book.
Watch comedies. Anything from favourite clips to episodes of favourite old sit coms or a whole hour of stand up by your favourite comedians. Try comedians you don't normally watch. Even they can make you giggle.
Aim to have 5 veg a day and 2-3 fruit. Make veggie soup - carrots, potatoes, leeks or onions with herbs or a handful of lentils and some spices, pureed.
Do 5-10 minute youtube or other online fitness classes - yoga or HIIT or target areas you want to strengthen or stretch in your body. You can also get great meditation, affirmations, Ted talks etc - 5-15 mins.