What do I do if someone tries to break into my house?

I live with a paranoid mother who thinks that someone is going to kidnap me but I am older, I am 17 years old and I know how to defend myself but she insists on leaving me locked in the house to prevent someone from entering and more than I have the window glued, but now I took away A duplicate of the key but it came to mind.
What do I do if someone really tries to get in?
Which is the best option? a knife or a shovel?
I am no longer a child, my father is not here and I have to become the man of the house.
What do I do if someone tries to break into my house?
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