<human>: Could you distill the essence of the text into 1-3 sentences?

So for some background, 

Recently my girlfriend is very stressed up by her job. She's one of the best performers in the office, if not the best, which is why there is so much pressure and high expectation from her boss on her that stresses her up. On a daily basis, she would voluntarily come an hour earlier and go home one hour later than the normal working hours, which none of her colleagues do, without getting paid overtime. It doesn't help that she's the over-achiever type and tends to take everything by herself. Because of this, she used to complain to me about how stressful her job is, which I really don't mind to listen since I thought it would let her let some steam off. 

However, few days ago she told me she decided not to disturb me and not going to complain about her job to me anymore since she doesn't want me to worry about her. Since then, I have been trying to ask her about her work but she wouldn't say anything. She would not even check her phone for my messages until she's off work. She would tell me she's very tired, got headaches, no appetites but when I ask her why or what happened she would just say nothing.  
 
Now, you would think that the first option for her is to leave the job if it causes so much stresses on her. Her reasons not to quit is because:

1. She just got this job last July so she doesn't want to leave so early in fear that her next prospective employer will ask her why she quit her previous job so early

2. She said she had a very bad, traumatic experience when applying for her current job due to immigration issue. (We are expats in Singapore) She said she doesn't want to experience that again

Personally, the first reason is understandable since it's really difficult to secure a job here so you just don't want to risk it but the second reason is just unreasonable and stupid imho. 

Anyway, I am completely at lost as to what I'm supposed to do. Should I let her be? Should I confront her?
<bot>: SO is stressed up big time by her job. Recently, refused to tell or share with me anything about her job. What do?