Boyfriend self conscious about not lasting long

So my boyfriend recently hasn’t lasted more then a minute, it’s not a problem for me because we do other stuff before and usually I’m all good if you know what I mean 😂😂

He’s getting so frustrated with himself and says that it feels amazing but just not for very long and he just keeps saying sorry after. I feel bad and want to help but I don’t know how.

He works 5am - 11pm most days and is completely knackered so we don’t have sex that often.

Any ideas?