I dyed my hair a dark brown last week and want to go back to my natural color. I bought color remover but so scared that it will dry/mess up my hair. I know I have to remove the color then dye it the blonde color that I want. Is it possible that my hair will fall out. I have had many people tell me that it will make my hair fall out.

I'll guarantee that your hair won't fall out. It might "break off", but that's different from falling out (it really is).

OK. Enough of that. Try a strand test. Lay a strand in the back, on a piece of foil. Apply the color remover to the strand. Let it process. Wait a week to see if there's any breakage. It's unlikely that there will be any (if it's a reducing-type color remover like ColorFix or Color Oops).