Hey bro if you're UK based (North East) dm me for resources.
I was homeless for 3 years and have cptsd and bpd too so I really feel for you.
General advice for anyone England based and homeless:
If you need a GP's but can't get one bc no home address - you can normally use a post office as your address and that helps with getting UC too as you need an address and GPs note.
If you have no ID most homeless resources can help you with that and if you can get in contact with citizens advice they may be able to help with everything from housing to finding and referring you to local food and warm banks.
if you tell a food bank you're homeless and what you have access too they'll give you food you don't need to cook/can eat out of the tin or can have with just hot water (some libraries and warm banks offer this for free).
If you tell a warm bank or free laureate (they exist for homeless and less well off people but they're pretty hidden) they sometimes have things like clothes, blankets, towels and sleeping bags that get donated.
Looking on local Facebook groups and pages for charities you can often find some resources too.
Oh and libraries! Use the bathroom sinks to wash, it looks stupid but wash your hair and give your self a fast whore shower (tits, pits and bits!) and that helps you feel a little less slimy.
Library cards are free, if you can get a post office address you can get one. Some libraries let you sign up without an address if homeless but not all of them do this. you can use the wifi for free if you have a card. And most have outlets that will let you charge your tech (and if you find a nice quiet area some works may let you nap during the day if your lucky)
I know it's so very exhausting to fight like this, especially when mentally ill, it's a hell I wish upon no one. I hope you manage to stay warm bro