Okay guys, so after nearly a whole day spent searching for ways to make this work I have finally, finally made it. So here's what made it work for me. I did everything mentioned in my original post, then I gave up with my google ID and made a new US based google account. Removed the old google ID from my device, did another hard reset and then logged in with my new ID. The US play store worked fine for a while with Tunnelbear for vpn, but then it went back to my local play store, and then started to crash repeatedly until it refused to open anymore. I was then fed up and put back my old google ID and removed the new one that I had just created, and guess what. Tada! It logged me into the US play store without any trouble. No need for vpn or any other fix. It's been working fine since, and fingers crossed it will forever.
So, what you have to do is log out of your current google ID, log in from another (new) one, and then remove the new ID and log back in from your old google ID. Make sure that before logging in with the new ID, update all your google wallet and google account details with US address, payment and phone number on your old ID.
Hope this was clear. Cheers.