In the f.s. book I have it mentions that a house on a corner with a road opposite is not favourable as cars approaching would shine their headlights toward the house causing unwelcome energies to enter. Advice was to hang a mirror on the outside of the house facing the road, that should ward off the energies.
Quite recently though I read somewhere that mirrors were never used in feng shui originally, so a bit confusing!!!!!!!!!

I know it may seem a bit drastic, but you did say that:

1) I have been living in my home since i was born and over the past many years i have very few, if any, happy memories.
2) I feel the negative energy permeating my home and the constant fights and frustrations that take place are of no help to the situation.
3) I have tried visualising 'throwing away' the negativity and others but to no avail.
4) The location doesn't help either - my house is situated in front of a T junction,
5) with a mortuary, in the front and
6) a chinese temple next to it.

All the crystals in the world couldn't get rid of the harm you are receiving from your environment.  That's like saying you love your home but it's under heavy power lines and built between a nuclear power station and a dump.  It's an extreme example but, hey, whatever works.  If it is prime real estate, sell and move to somewhere else.  Just make sure you do some research of your new environment before you do so.

BTW, mirrors and ba guas do not "deflect" harmful chi.  That's just superstition.

Good luck!