Don’t be worried, be realistic, he needs help, he knows it, he’s been here before. He knew it long before you did. Do you want to help him or give up on him? Presumably it’s the former as you’re here being brave enough to open up.
Do we know you’ve proved strong and able enough to deal with this. If someone’s gonna have a relapse, then at least this time it’s likely been triggered by this abnormal world we are all now in. Yes he needs help, if you want to be be the first rung of that ladder, then give him a chance to relax. Explain you know where you both are, and as of now you’re both going to beat it once and for all.