If you have no one to talk to, try writing it in a diary or try to stay occupied with something that you really enjoy.
Writing down in a diary is like talking to someone and you can be as open as you want. Of course it might not be as good but at the least you don't bottle things up; it'll make you more stress.
Being occupied with something makes you concentrate on a different matter and still keeps you brain going, It could range from just reading books or going out to exercise and do activities. This method might not work away but you should still try it out so instead of mourning or keep remembering those things. Once you feel better, try to come back and address those problems, you might have a different point of view of them by then.