Needing some advice...How to read this woman

It is a long distance relationship as I met her when I traveled for work. She knows my income is just average, she knows I will not marry and my life is very simple. Now with her, She is very educated, quiet and a little shy and attractive (in my view). She lives out of the country and has done everything she can to get a Visa and she has succeeded because of her job. So why me???

But everytime I say I want to go step by step in this relationship, she is very defensive.
If I say anything wrong, I get the silent treament and will not even talk about it. Is that normal?
She hates when my family member asks questions to her
Thriller movies are her favorite (does that mean anything)???
If she is not working or in school, she spends her entire time at home with her parents.
She is online chatting with people and never goes out to see friends.
She has spent her entire time to make it on her own to come just to be with me (which sounds nice but maybe is obsessed)

She had a small health challenge when she wanted to lose weight, but was very open with that the first time I saw her.

But most of all her mood swings are somewhat extreme...But never yells
In all, it makes me feel she has a motive or something hiding.
I feel as though I am in danger when she comes here because it feels like an obsession of hers.

But at the end I do like her when we are together traveling and alone.. It is so different.
Am I just being paranoid?? I just never had this before. Why does she not give up? Always coming back after I say, maybe we should stop. She does not beg, but does make me feel guilty.

She is either a true genuine person, or psychopath.

Thanks for any opinons....As I say, I could be over reacting.
Geo

Oh my... when you suspect your girlfriend of being a psychopath, I'm sure it's not a good sign :))
Well, she might have some problems or maybe this is simply her way to be. Have you talked to her about it?

To be honest she sounds like a loner. She likes her own company but she obviously likes being with you! She is insecure, that's why she yells at you and gives you the silent treatment. She is different, but that can be a good thing?