Of course it is completely normal to be exposed to stress and demanding situations in life, but it is also possible to protect oneself from such situations, for example by learning preventing relaxation procedures (e.g. progressive muscle relaxation after Jacobsen, autogenous training or also Yoga). So-called stress mastering training, which is offered by some health insurance companies or other associations, can also be valuable.
However if sudden changes occur (e.g. separations, issues at work, diseases etc.), this can result in a so-called adjustment disorder, which might require psychotherapeutic assistance.
If this kind of crisis occur and you need acute help, it might be good to talk to someone right away. If this would not be possible within the family or circle of friends (or other desired), there are special phonelines to call, church associations or also advisory boards on the Internet for appropriate short term assistance.
If you are having thoughts about suicide or aggressive impulses you should not hesitate, to call the medical emergency services or the police. In this case, it could be life-saving to go and see a psychotherapist who is a trained expert and can help you with the acute situation and help you to see the problems from a different view.