Nothing has injected you with anything. Severe mood swings and a destructive nature can be caused by many things, and none of them is a demon injecting you with anything.
Adolescence is often related with mood swings along with underlying medical conditions and mental issues.
I would recommend putting it out of your mind and seeing if it decreases.
if it doesn't then, does anything make it worse? better?
Take note of what effects it and if it recurs frequently, go to a doctor.