A lot of us suffer from this
@Mattymatt , please don't be too hard on yourself! I can cook well but struggle and am not good at all at all the clean up after and other day to day housekeeping tasks.
There are a ton of great suggestions above, the good thing about cooking is that you can follow instructions and not really have to think for yourself with recipes and there are a vast array of recipes of every kind on the net.
I know for me, I feel much better when I push past the inertia and resistance and do something unfamiliar.
I used to be clinically depressed and, basically, doing hard things and unfamiliar things, even though they are scary, I found the best way to alleviate depression. Every new thing attempted, even if I started our bad at it (that's, pretty much, to be expected) improved my self esteem, because I was being brave and action brings a sense of empowerment and with self esteem and a sense of empowerment, improved, the depression alleviates.
Cooking, something palatable maybe a lot easier than you think it is. Or even just add something healthier, some steamed vegies or salad to what you are accustomed to, makes a big difference to one's health and wellbeing.
Tastes can change as your body can recognize food that is good for it.
I'm suspecting that even just adding some healthier foods will do wonders for your mood and health.
I have a book about foods that combat depression, things like berries, fish, oats, vegetables, and it has recipes in it too.
Good luck with making some healthy changes! I feel confident that doing so will bring added wellbeing and health into your life.