I think it is the same as i can't stand. For exemple: i don't like rice because if i eat rice , i am ill so then i don't like to eat because i can't bear it or i can't stand it. I don't know if you understand me or not. Thank you very much.

Hello Anna "I can't bear it" means that something is overwhelming. It may mean something is so horrific, that I cannot bear to watch it, or think about it, or try to solve a problem, or something to that effect. One might say that if someone wants to break off a friendly relationship (for example) that "I cannot bear it!". The opposite response would be to simply say or write; "I do not care."