Reddit bans people for using a VPN, so you might have been banned for that and not tracked back to your original account. Get a residential VPN/Proxy, they are usually a bit pricier than the normal ones, or just go to a friend's house and use their IP to register.
Not that it will help in the long run. Their AI is running rampant. If it doesn't ban you for this, it will ban you for that, or for a myriad of other "reasons".

A place where you can rent a PC. Any regular internet cafe or a public library should work too.