I asked on a Facebook with the video I'm linking below, how could I do something like it as it was impossible to do without a hairband or something sturdy underneath.
A belt was suggested and it worked perfectly!
I used 2 of these in the same width, cut one belt in 2 and glued it to the ends of the complete belt so it wouldn't be bulky near my forehead.
And I followed this tutorial on mute because I'm not really sure of the language, but it's do able by just watching, I did a short step by step with photos
Orange was the pink and purple was the black because it's darker, I used bias tape because it was the only matte thing I could get locally that had the colours I needed. I'm pretty sure I got 5.5 meters (550cm) of each colour the finished headband is roughtly measured as 2 meters (200cm) and I had a bit left over.