Hi there,
I think that you will need to slowly start teaching your dog that being left in the crate during the day is no big deal. You could do this by gradually leaving him in the crate for longer and longer periods of time.
Start by leaving a few treats and some toys in the crate, and then encouraging your dog inside. Close the doors and quietly leave the room. Wait for a few minutes and then come back inside and without making a fuss, let your dog back out of his crate.
Practice this as much as you can, and hopefully you will find that he starts to get used to being in his crate during the day.
Try not to leave your puppy in the crate for too long because he is still quite young, and probably can't hold his bladder for too long during the day. You don't want him to get into the habit of relieving himself in his crate!
Good luck
