\[ y''(x)=-\cot (x) y'(x)-\frac {1}{4} y(x) \left (-17 \sin ^2(x)-1\right ) \csc ^2(x) \] ✓ Mathematica : cpu = 0.100006 (sec), leaf count = 33
\[\left \{\left \{y(x)\to \frac {e^{-2 x} \left (c_2 e^{4 x}+4 c_1\right )}{4 \sqrt {\sin (x)}}\right \}\right \}\]
✓ Maple : cpu = 0.045 (sec), leaf count = 22
\[ \left \{ y \left ( x \right ) ={({\it \_C2}\,\cosh \left ( 2\,x \right ) +{\it \_C1}\,\sinh \left ( 2\,x \right ) ){\frac {1}{\sqrt {\sin \left ( x \right ) }}}} \right \} \]