Hi FruFru, it's hard to imagine how your DH is in himself with little info. Does he do a hard manual job, desk job, have a tough boss? Is he the type to work longer by nature rather than a more disciplined type who'd out the door asap?
No one person is enough to make another's life so I hope that you are interested in some things of your own.
If he's on a treadmill at the moment, what about buying something for him - a little treat he'd not buy for himself, eg a book, a massage, a facial, a plant, chocolate, something for himself. Wrap and handover at lunch saying you know hes busy and no time to treat himself, acknowledging his current routine. Without creating an agenda, the conversation might open up w bit then, or later and you could do as others have suggested and look towards time away.
A walk in the country, by a river or the sea with a treat tea or meal could be relaxing.
Good luck