Launcher shows nothing

So I didn't play minecraft for a few months and appears that it became a mess.

First I had Problems with Mojang's new Account stuff, because I bought the game years ago with my mums creditcard, which has been replaced and I didnt save the Confirmation E-Mail, so yeah that took like a week.

Now I installed Minecraft from the new Website for the first time and it wont work.
The game just wont start properly, all I get is this White or Grey screen u can see in the attachments, I found multiple Threads about this Topic here, but non was attached with an Answer that offers a Solution.

The Nativelog ends with "assuming all's fine", great Mojang.