Who hurt you? That’s not at all how you treat someone who very clearly has something going on and probably has 0 other support to get through it.
Other comments are right. Stop enabling or allowing unhealthy foods to come into the house. Sit down and talk with him about how he’s worried for him and he wants him around to experience life. You cannot make choices for other people and you can’t expect sudden change but to just throw someone on the street? Absolutely not. Man if my family did that to me when I was deep in depression and gaining weight I wouldn’t be here right now.
OPs brother could be suffering from some undiagnosed mental illness due to COVID trauma. Collectively as a world we endured something catastrophic and people have had different ways of coping.