The world is full of toxic people. And who are the toxic people? For there are several classes, from the least harmful to the most malicious:

Passive Toxic Persons: Victims, is the person who blames him for all the bad things that happen to the people he has around him. They are not responsible for the bad or the circumstances that cause it; they feel mistreated by life. Kind of anticipating failures.

Critical Toxic People: Your life is so gray, frustrating and boring that you live by living the lives of others. They do not mind destroying everything that surrounds them, the positive assessment towards others is not in their vocabulary.

Toxic People with Bad Ideas: HUYAN OF THESE PEOPLE. They are resentful of Life; they interpret everything for the worse.

Psychopathic Toxic Person: Inflicts pain on others without feeling the least guilt, without having a bad time. All those who humiliate you, disrespect you on purpose, tell you that you are not worth, they hit you, they threaten you and cause you to feel ridiculous and a "shit". Go running, the one who does it once, repeat.

How unpleasant it is to listen / live with a toxic person, that's why, I'll leave you three (3) tips to deal with this kind of people:

1.-

When a friend is "bitter" because he only talks about their problems and their sorrows, he does not ask you about how you or your family is doing, he calls you to let off steam and also does not listen to your advice ... STOP. Tell him that enough is enough, that he has to take charge in the matter, that complaining is fine to let off steam, but that the next step is to ACT. Tell him to support him as long as he is mobilized, but until he takes action on the matter, you do not want to hear one more penalty. And if he gets angry, he has two problems. I assure you that you do not lend him any help if you reinforce his whining behavior. It will remain a parasite throughout life.

2.-

Do not allow me to criticize other people who are not present. If you do it with others, it will also do it with you when you are not there. If he gets angry, it's his problem. It is more important to be ethical and a good friend than to avoid a conflict with someone who is toxic. Anyway, sure if it is not this, you will find another reason to get angry with you.
When the toxic person is dedicated only to talk about problems, make him reflect and ask him to think about solutions. It spends the same energy and gray matter, but while the first consumes and subtracts, the second option contributes and adds.

3.-

As a last tip, but, not least:
Do not let anyone disrespect you, let alone harm you psychologically or physically. You are a worthy person and only for that you deserve to be treated like a person. It is not shouted, or stuck, or insulted, or belittled, or humiliated, or compared to anyone. Make yourself worthy, because if you do not do it, even those around you will think that is your value, or zero.