Fear keeps you alive...
Personally I think it is normal to feel scared and have a heightened sense of arousal when in IMC, particularly when crossing through a frontal system or flying an approach in real IMC.
On Monday night I shot the ILS into Plymouth after a night/IFR flight back from Jersey. Overall the weather wasn't too bad but we were IMC in and out of cloud, out of sight of the surface and in constant rain/mod TRB (no ice at our level).
We broke out at about 600ft, but in that couple of mins before I was all eyes on the instruments watching over all aspects of the approach.
The GS wasn't picked up by the autopilot so I hand flew the approach (rather than sitting back and being a manager which is how I prefer to play things).
I got home at 10.15pm but couldn't get to sleep for a couple of hours - I was buzzing too much.
When I was very new to IMC this would have absolutely terrified me. It still frightens me but I am more used to it and sure that I can fly the go-around and divert if necessary.
Fear keeps you alive. It is a positive Darwinian trait.
SB