It's hard to know what you want so perhaps my tips won't be suitable.
If you don't already, bath or shower daily. Wash and condition your hair at least twice a week. Brush your hair daily. As well as cleaning your teeth. There's something cleansing about water even if there's no soap involved, the feeling of your worries going away down the drain is relaxing.
Get some face cream with SPF in it and use it every morning. If you want makeup but don't know where to start, try BB cream, with lipgloss and mascara. Take it off in the evening and use a night cream. You could do your entire face care routine in the morning in the time it takes for the kettle to boil.
Get a glass nail file, they're the best type for not causing snags and they never wear out. Get a nail buffer, it's a block pad with different colours on, each colour is a different harshness. The instructions will say how to use it but essentially you rub it over each nail in turn, using the hardest sides first every week and the softest side use daily. It takes a few minutes daily and makes your nails shine without using polish. You could do it in the morning while your tea brews.
Sounds like your wardrobe needs an overhaul. If it's all tatty put it out for recycling. Get some new underwear and socks, a week's worth. If you're fed up of jersey fabric and casuals, how about a shirt dress, perhaps with a belt? You could just get 5 black ones so it's not too out of your comfort zone. Maybe get one lounge wear outfit for a relaxed day off when you're just pottering about. So your laundry twice weekly and you won't run out of clothes.
A new bag, shoes and coat would complete your small wardrobe for now. You can then consider what else to buy as you start feeling better about yourself.
Have you thought about getting out into nature? Its proven by scientists to be beneficial. Walking, or presumably sitting, amongst trees means you take in chemicals they give off and that does something beneficial to your brain, you could explore all the public parks and woods in your area. Gardening is good because bacteria in soil gets in through your skin and does something good to you. Maybe try making a hanging basket or growing some veg in a pot if sorting out an entire garden sounds too huge a task. Sorry I can't remember all the science type details!
Yoga, from a meditative point of view is good for calming down after a stressful day, and for peace and tranquility. It's about moving in time with your breathing which somehow calms your brain. It doesn't matter if you're so stiff your movements are very small, it's not about what you can't do, it's about doing what you can and respecting your body's limitations. Leggings and a tee shirt would do for an outfit.