I am in the same situation as you do. I think that the salary is not important part in one's life, you need to relax. but you should see how much is the work load your boss assigned to you, if the work load are the same as other people who has higher salary than you, then you talk to your boss, saying that you can't handle it it is too much, he/she will know what you mean.That what I did, i don't care about salary, but i do only the amount of work my salary told me to do.
It is also important to see who is your competitor, chinese or american, mine is a taiwanese.