Unable to purchase anything on Steam

Your mom blocked your acc to purchase

I've been having trouble with steam all day

venom id close every instance of steam and including processes to make sure it isn't hung with a secure connection preventing further instances of the checkout to process

also depending on how far you got before the issue occured, you should go check your bank account or whatever to make sure the money wasn't taken.

Just keep it in the cart and give it a few hours, the sale just started so there isn't any reason to rush

scan your pc thoroughly just to besafe .
you might have a root "virus"