What does a dead black bird mean? ive seen 2?

okay the first on was in my back yard and i baried it with my friend..( im 14) the second was on my front doorstep!!! im scared because ive been having bad health all year and for the past 3 days ive been feeling like my bones are weak, ive been achy everywere, and honestly i feel like whenever i barely get hit something is gonna break... ANYONE WHO IS AN EXPERT IN THIS STUFFF PLEASE ANSWER! im scared, and my bro has been having bad depression so this makes it worse