I wouldn't risk human ointments, personally.
While waiting for the vet to come, if you have another sheep-keeper, or a dairy farmer nearby that you can ask, you could try to get some Orbenin cream. It will soothe and may heal, depending on the cause of the infection. (It's used for eye infections in sheep, cattle, horses, dogs and cats, and also for mastitis in cattle - hence why a dairy farmer may be able to help
)
Otherwise, bathing in cooled boiled water will probably provide some relief.
And of course, if you can take and post a pic, there may be other ideas from the folks on here