\[ y''(x)=-\cot (x) y'(x)-\frac {1}{4} y(x) \left (-17 \sin ^2(x)-1\right ) \csc ^2(x) \] ✓ Mathematica : cpu = 0.0890356 (sec), leaf count = 37
\[\left \{\left \{y(x)\to \frac {c_1 e^{-2 x}}{\sqrt {\sin (x)}}+\frac {c_2 e^{2 x}}{4 \sqrt {\sin (x)}}\right \}\right \}\]
✓ Maple : cpu = 0.044 (sec), leaf count = 25
\[ \left \{ y \left ( x \right ) ={{\it \_C1}\,\sinh \left ( 2\,x \right ) {\frac {1}{\sqrt {\sin \left ( x \right ) }}}}+{{\it \_C2}\,\cosh \left ( 2\,x \right ) {\frac {1}{\sqrt {\sin \left ( x \right ) }}}} \right \} \]