Rejected petition Home Self Defence

The details on how one may protect themselves and their loves ones within their own home/property is extremely sketchy and very difficult to understand. It is very possible in the heat of the moment if someone breaks into your home you panic, as you realise "what can I actually do to defend myself that won't make me a criminal" I say these thoughts should not be going through the mind of someone who could have themselves or their families harmed by this person.

I would like to know, 100%, what can I do to ensure my safety, and the safety of others within my home, if I take a knife out of my cutlery draw and defend myself with it, the police could turn round and say "you used that as a weapon, it was not self defence, you are guilty of GBH". This will potentially destroy peoples lives, any hope of a career with a criminal record and destroy peoples faith in the justice system within this country.