AIBU to not know how to respond?

[UnfriendlyFriendly]

A friend (let's call him Ollie) has been talking to someone online since the end of March. Three weeks ago, they met up in person and slept together. Ollie was due to see her last weekend but she text him last Friday saying she's no longer interested in a relationship with him. Ollie was obviously upset so I spent a few days with him, talking through it etc. We've been phoning each other and messaging each other over the last week and he's not getting any better. He's made references to suicide, saying that he'll never be happy again, that his heart is shattered, that he's a shell of a man etc etc.
I really want to be supportive and to help him but, truthfully, I feel like he's being completely absurd. He's met this woman one time. I can barely formulate responses anymore because I just feel like rolling my eyes.
WIBU to tell him (kindly and gently) that it's ridiculous? If it is unreasonable to do that then how do I respond?

He is having a disproportionate response.
I think you'd be fine to point that out to him. You can acknowledge it hurts, he's hurting. You can say that you think it's tapping into bigger things.
You can say you have the skillset to cope with a break up. But you think he needs more help and should contact GP for his mood cos he's not the guy you know atm.
OLD is fucking harsh. Everyone saying get a grip and get over it probably has no idea of what it's like and how tough lockdown has been mentally on single people.

I think what @PicaK suggests is the most helpful way to handle it.

@DotsandCo

Yeah, I seriously couldn't deal with this...I'm obviously not a great person! I'd have run out of patience by day 2 I'm afraid! You're a much better friend than me OP, all credit to you. Ollie needs to get his act together and move on...this is bonkers! He had a date and a shag with a one night stand ffs! Just tell him to get over it already, you're all out of fucks to give him!

This would be my response 😂

If I continue the facade that it is reasonable and that his devastation is an appropriate response then it very much shies away from him getting any help. But I can't really say "get some help" without him getting defensive and turning away.

I totally understand this dilemma. I've been in the same situation (though it wasn't OLD related) with a friend. I was the only person that he opened up to about his problems and I was terrified that I would drive him away if I challenged his thinking, and he'd have no-one.
I wish I had the answer. I really wasn't much use at all.