First to explain what happened, I suppose.

I am 16. Ever since I was little my mother has fought many different kinds of cancers. She's gotten through all of them but it's still extremely stressful. Just this past couple years she had skin cancer in her throat/back of tongue. She got radiation and chemo therapy. Which was hard for me to see her so sick and I couldn't do anything about it. During the recovering stage she got infections and had a horrible cough. This year in May I was doing my normal stuff and then she starts coughing a ton and it sounded to me like she was throwing up so I pretended to ignore it. I can't stand the sounds. But then my dad starts yelling at me to come in the kitchen and help. Then I got scared and I couldn't really move and my mom was struggling to tell him not to get me involved because it would scare me. So I just kind of sat there confused, not really knowing what was going on. But not really wanting to know. Then he yells at me to go wait outside for an ambulance. So I go outside and sit on the curb and wait, still not knowing what's happening. (You would think I would know by then but no.) Then they show up and go inside. Even after they left I didn't go back inside until a black cat came up to me being cute so I bent down to pet it and it hissed at me and I walked away and it followed me. So I go inside. Turns out she was coughing up blood. Not a little though, so much…it was really scary. She stopped for a while and she came up to tell me it was okay even though I knew it wasn't. They then traveled to the hospital. I don’t remember exactly how I felt, other than being terrified. My dad told me I looked so scared like my eyes were huge. After they left I just did what I usually do. Video games, youtube, pretty much anything to make sure I wouldn’t do anything bad to myself.
My mom had to get a 10-hour surgery to reconstruct her throat because it was basically deteriorating due to the radiation. Now she has to breathe through this tube thing in her neck and eat through a feeding tube. Not exactly the prettiest things to see.

So now I can’t stand to hear anyone cough really hard. Especially my mom. I internally start to freak out if I feel like it will happen again and I get some weird, almost choking feeling. Like I can breathe fine but it’s just tight. I do have hypo thyroid so maybe it’s from that but I don’t know. I’ve looked through the symptoms of PTSD on this site and I have 90% of them.

. Frequently having upsetting thoughts or memories about a traumatic event.
(They usually happen at night when I’m trying to sleep. My brain just wanders and it goes to it a lot and then I can’t stop thinking about it)
. Acting or feeling as though the traumatic event were happening again, sometimes called a "flashback."
. Having very strong feelings of distress when reminded of the traumatic event. (I usually feel very sick)
. A loss of interest in important, once positive, activities.
(I’m in marching band. Last year I loved it! This year I would do anything just to skip practice.)
. Feeling distant from others
. Feeling as though your life may be cut short.
. Having a difficult time falling or staying asleep.
. Feeling more irritable or having outbursts of anger.
. Having difficulty concentrating.
. Feeling constantly "on guard" or like danger is lurking around every corner.
. Being "jumpy" or easily startled.
All of these have been going on for more than a month

Also, I’ve been very paranoid. I always feel someone is going to randomly pop out of nowhere and shoot me with a gun. I usually feel like this at night when trying to sleep. Like I said earlier, my mind wanders and ends up there. Or when walking around I always have to look behind me because I think I see a shadow or I hear a noise. Only way for me to stop thinking about it is to play a video game. Even then, sometimes it’s hard.

So…I’ve been thinking about getting some help. But I don’t know if I can tell someone in person how I feel to some random person I don’t know… and I don’t want to tell my parents that I want help. They know about me being paranoid but not about how I feel about my Mom. It would kill me inside to tell them “I feel distressed because of what happened to you, Mom.” I think it would make her feel sad and that it’s all her fault…

I've asked around before and people say "you're feeling normal human things. it's nothing to worry about. everyone would feel the way you do. you're just feeling anxious about if it'll ever happen again" So then tell me, what makes someone have PTSD?

I’m very sorry for the extremely long post…