Are gambling in casinos, playing matka gambling, buying lottery tickets and lending money on interest sins to be confessed?

Buying lottery or gambling at Casinos is not inherently evil. But these could easily grow into an obsession as there is a prospect of easy money. It can prevent a person from meeting legitimate obligations to himself, to others, especially the family. If you are referring to a one off incident, then it is not a sin to be confessed. But if this has become  a compulsion and is affecting your life and the life of others, it should be taken to the confessional and seek ways to get rid of the risky habit.

Catechism in CCC 2413 says “Games of chance (card games, etc.) or wagers are not in themselves contrary to justice. They become morally unacceptable when they deprive someone of what is necessary to provide for his needs and those of others. The passion for gambling risks becoming an enslavement. Unfair wagers (betting)and cheating at games constitute grave matter, unless the damage inflicted is so slight that the one who suffers it cannot reasonably consider it significant.”

As far as lending money is considered one can receive a just and legitimate interest without exploiting the borrower. Usury or lending money at unreasonably high interest is condemned by the fathers of the Church such as St. Augustine, St. Ambrose. Catechism (CCC 2269) says “Those whose usurious and avaricious dealings lead to the hunger and death of their brethren in the human family indirectly commit homicide, which is imputable to them”.