ETA a warning that this is a ridiculously long response and I may be totally projecting myself onto you, Mander. I hope I haven't overstepped, but if I have, I humbly apologize and please just disregard me. <3 I will probably delete most of this post in a few days because it's a bit personal for me to leave on the Interwebs for all eternity.
*hugs* Mander. First off, one practical suggestion--I know you said you can't seem to differentiate between your items, but is there possibly even one or two pieces of clothing that make you feel good, or at least okay--not ashamed or embarrassed? That would be a starting point. Then wear that outfit or combination as much as possible, partly just to help you feel better about yourself! And go from there. Posting keep/toss threads can really help, too.
Now I am going to over-share a bit because I want you to know you're not alone. It's OK if you don't want to read my ramblings.
I know what you are describing--I've been there, many times over, and it's not fun, to put it very lightly. Unfortunately the result is that I don't have much good advice to offer--but you have all my empathy and sympathy and undestanding. One of the primary sources of my lifelong struggles with depression and anxiety relates directly to being bullied as a child for years because my clothes weren't trendy.
I still struggle hugely with this when it comes to selecting clothes, putting outfits together, and seeing myself clearly. Some days I do really well and others, not so well--and getting to this point, where at least *some* days are good, has been a years-long process for me.
The great thing is that I've realized that when I *do* hit upon an outfit I really feel good in if almost functions as a kind of therapy; I feel much more confident and capable in other areas of life as well.
The thing is, I can only experience that when my mental health issues are at least moderately controlled. If I'm actively, diagnose-ably depressed and/or anxious, my self esteem is thoroughly trashed and no amount of pretty clothing will lift me out of that. I cannot see myself or my life clearly and everything just spirals down to guilt, shame, fear, embarrassment, helplessness, etc. It sounds like that happens/is happening with you, too.
I'm going to gently suggest that you focus as much as possible on addressing your depression (which is probably the main cause of your self-esteem struggles--and the self-esteem struggles feed into the depression--it's an evil cycle). Have you been successfully treated (whether with meds, therapy, diet/exercise, meditation, some combo... anything) before? I'm not an expert at all but if you want I'd be happy to share about some of the things that have worked for me.
When your depression starts to lift, I'd bet money you'll be able to make more progress with your closet. Until then, go easy on yourself. Really, really, *really* easy. Maybe even take a break from trying to sort out your clothes. If you're going to try to tackle them anyway, do something positive first, like watch a movie you love, so that you're in a good headspace going in. Put on happy music and wear sparkly eyeshadow, or something else that makes you feel good.
\\