booting up my Macbook using option key and power on results in white screen with mouse I have a Macbook Pro.
I installed Ubuntu and wiped all the partitions in the process (fit of rage and getting angry at OS X)

someone told me to "clear PVRAM by holding Option+command+R+P"
I did, this, now not even my ubuntu loads up.

when I turn on the computer i get a white screen with a flashing folder with a question mark in the middle.

when I boot by holding the option key, all I get is a white screen with a mouse pointer which i can move around.

I have created a bootable USB drive using instructions from the below, although unable to boot from USB.
http://pureinfotech.com/make-bootable-usb-mac-os-x-windows/

How do I go back to OS X (or even Ubuntu, so I can at least have a usable machine)

This question is close to my situation, but I exhausted the things that fix that issue:


My MacBook Pro has a flashing question mark in a folder against a grey background


Specifically:


My bootable USB doesn't work (so I need Mac OS to make a new one
I cannot get to the recovery tool or the Disk Utility. I've clearly deleted the recovery HD so Command + R fails to load a now missing recovery tool. 


Ubuntu was working fine before i cleared PVRAM. Even with Ubuntu, when I started with Command+R, I get taken to a white screen with a mouse on the screen that I can move. This, I would say, rules out HDD issue (unless clearing PVRAM can destroy your HDD)

Once clearing PVRAM is when I get the folder with the question mark, and Ubuntu now doesn't even load.
Now that an external boot recovery or internal recovery is out of the question, you have two options. 


Try Internet recovery. Boot with option + command + R held 
Take this Mac to another Mac, use disk utility and run an installer over target disk mode
Find another Mac to make a recovery USB drive or bootable installer. Recovery is smaller and does less. Installer is larger and does everything the recovery does plus has the install package to reinstall the os. 


https://support.apple.com/en-us/HT201372 - bootable installer 
https://support.apple.com/en-us/HT202294 - recovery assistant



Internet recovery doesn't work on all older Mac hardware. Some protected wifi  / fire walled networks prevent internet recovery. It works in most home and public wifi situations quite well. Try that first. 

Target disk  varies depending on what specific Mac you have. Some work over USB, some work over FireWire, some work over thunderbolt, some work over more than one of the above.

The option of just making a bootable installer or a bootable recovery USB drive will always work assuming you pick the right version of macOS for your specific Mac.