Mental illness. If anyone can tell.

My fiancé is mentally ill.He left his job. He thinks he can change the world. He started taking much more marijuana. He constantly writes on a paper randomly. He leaves home at any time and tells no one. He is constantly switch talking between ramayan bhagvad geeta and constitution . His thoughts are not stable. We tried giving him medicine but he angrily thow them out . He left eating at home and he eats mostly outside home. He ruined every single penny bought new phone without any reason and booked 5 star hotels several times. He doesn't sleep much.Constantly calling random people and talk non sense. This all started in the month of march just after the kashmir files released and he watched that movie (he took it so seriously i guess) . Any suggestions we are so worried if anyone can tell .