Find the value of $$\frac{8 \sin 30^\circ \sin^2 60^\circ - 4 \sin 90^\circ - \sec^2 45^\circ}{\tan^2 45^\circ - \cot^2 30^\circ}$$.

A

$$-\frac{1}{2}$$

B

$$\frac{5}{2}$$

C

$$\frac{3}{4}$$

D

$$\frac{3}{2}$$