Start talking. It will make me feel awkward

For some reason I think people only interact with me to make me feel awkward. Its seems to happen a lot.

ROTC boy: "Did you change your hairstyle?"
Me: "Um no? I just got ready today"
ROTC boy. "Hm yeah maybe that's it" 

Girl that greets me with a huge smile: "Are you excited for Halloween? I am!!" I then noticed her very real looking acyclic VAMPIRE teeth
Me: Uh......................................

Physical education teacher: "Oh hi Sam!"
Me: "Hi! Wait, I'm not Sam....."
Physical education teacher: "Are you sure? You look just like her"
Me: "Yeah I'm sure"

Me: "Can I help you?"
Red head boy: just stares at me
Me: feeling super weird. "Sorry, can I help you with something?"
Red head boy: "No"
Me: "Oh...okay"

Another ROTC kid: "RAWR" (he popped out of mid air)
Me: Jump ten feet and have my heart stop
Another ROTC kid: "Did I scare you?"
Me: "Yeah you did"
Another ROTC kid: "ha ha ha ha ha ha" and walks away