Hi there
As a vet, I can tell you that the droopy face, mouth open, tongue out sounds like facial nerve paralysis. The nerve that controls the muscles of the face passes through the ear area, and if damaged, will lead to that side of the face drooping. It would fit with blood coming from the ear that there has been some direct trauma to that area, either a knock to the head that's caused bleeding, potentially something like a crow pecking at the ears, or even a bad infection, though ear infection would be rare in a young lamb.
If he is doing well, walking, keeping up with mum, and is able to feed, then he should be just fine - just keep checking this as he may struggle to suckle a bit if the lip is drooping, but the tongue should still be able to work normally. If there has been a direct damage to the nerve, such as a trauma, then it may never recover, but if the damage was around it, and swelling only is causing the nerve related problems, it may settle down with time.
I hope with your TLC he'll do just fine
Suzanne