It seems to me that you are being a great friend. You’re showing him that you are concerned and that you care and are there for him. It is the fog of depression that is not letting him see that. In fact it’s got its grip on him so bad that it’s making him think you are a threat. This is not your fault. And it’s important not to push too much because it might actually make it worst.
Maybe just give him some space but pop your head into his world every now and then letting him know you’re there for him when he needs you. Bring him a nice treat or invite him out for coffee see if he’ll accept.
Best wishes and stay safe.