Calculate voltage in a alternating voltage circuit
I think the issue is with the parallel calculation of R and ZC2.

I agree that ZC2 = 0-j66.667, but putting that in parallel with 5+j0 yields:
Z2 = 1/(1/R+1/ZC2) = 4.972 - j0.3729 or 4.986 at an angle of -4.3 degrees

From there, just multiply your input 0.3 @ 18 (radians?) by the impedance divider Z2 / ( ZC1 + Z2 )

I get 0.0439 at an angle of 77.32 degrees.  Of course you still have to add back in the phase of 18 (by default such an equation would use radians - though 18 is an awful lot..., but degrees are usually specifically called out if used)