Tiling texture gets weird

Hello,

I am trying to make my own texture, so I made a simple one in Gimp to test with, exported it as PNG and imported it into unity.

Then it got weird. I created a simple plane, and added a material with my texture to it, with default settings it looks okay, but if I want to make said plane bigger, the texture gets stretched and does not look good.

This is why I tried to make the texture tileable (still learning). However when I set it to tile I get the following result:

Can anyone see what I am doing wrong here?