Problem:
Here is what I've tried:
I drew symmetry of $BC$ and $AB$ along $AC$. Now $AE$ is angle bisector of $\angle DAC$. It seems it is enough to only consider $\triangle ACD$ and segments in it, but I still can't see a connection between orange segment and green segment.



As in comments, you already solved using law of sines. Here is a construction that shows $x = y$.
Extend $CB$ and drop a perp from $A$. Also drop a perp from $D$ to $AC$.
As $\angle ACE = 30^\circ, AE = AC/2$ and $\angle ABE = 50^\circ$. Also, as $\triangle ADC$ is isosceles triangle, $AH = CH = AC/2$.
That leads to $\triangle ABE \cong \triangle ADH$ (by A-S-A) and hence $x = y$.