I would say the main tip is to make things as easy as possible for yourself, at least to start, so you're not fighting an uphill battle and making loads of huge changes at the same time.
So set up a supermarket delivery automated once a week/fortnight with easy food options that you don't have to think about, so you don't need the takeaway. Even if it's not all amazingly healthy stuff - a supermarket pizza is still significantly better than dominoes, a microwave curry better than an indian etc. Beans on toast or ready made soup better again.
Skincare - there are companies that do analysis of your skin type and then deliver the products to you, perfectly tailored for what you need. Sorry I can't remember the names atm but I'm sure there are money off codes on style&beauty. Again, make it as easy as possible so you're not overwhelmed in a shop. In terms of hair I've got the opposite problem (PCOS so too much of it!) but I know lots of people recommend those caffeine shampoos to thicken hair?
Shower - the best way is to just get into a routine the same time every day (whether as soon as you get up or before you go to bed) so you don't even think about it. Like having getting up and going to the loo in the morning - it's not a treat you can deny yourself or a chore that you can put off, it's just something that's done for the day. Can be a really quick one - 1 min is better than nothing. Maybe buy some really nice smelling products, or put a shower radio in there if you like music or a really interesting podcast.
Get outside if possible at least once a day. People roll their eyes and say exercise isn't the magic cure all for depression - but nobody actually says that it is, just that a change of scenery, fresh air and getting your body moving (just a slow walk!) is almost always beneficial, even if it's "only" taking you from -10 to -2. Going outside has sometimes made me feel loads better when I'm struggling, sometimes not much difference, but it has never, ever made me feel worse.
Could you get a dog? The need for daily exercise plus the confidence boost of something that thinks you are absolutely amazing can be a game changer. Maybe look into fostering/dog-walking/dog-sitting to start if you don't want to commit fully? Again, great music or a fascinating podcast can help because you're retraining your mind to think 'If I go now I'll get to find out what happened to the murderer (or whatever!) oh yeah and I guess I'll be walking while I do it,' rather than 'Ugh I suppose I should go for a walk.'
But above all, be kind to yourself. Life is hard. If you have one bad day where you don't do any of the above, then that's all it is, one bad day, and you can try again tomorrow. ❤️