Dear Chris,
Your letter really saddened me - the two most important words, vocation and motivation, just did not appear.
Why did you decide to become a veterinary surgeon? Because of the challenge of getting into vet school and you were clever enough to manage it?
'On-call duty is no fun' - by definition, almost, many duties are 'no fun' - they are not meant to be, but unitl we can stop animals needing help at 'unsocial times' it has to be provided.
There are very few jobs which involve working with animals which are highly remunerative, be thankful that you are not a dairy farmer working longer hours for a fraction of the rewards you are getting.
A veterinary qualification can open doors to many jobs - to quote Normal Tebbit, get on your bike and go and find one that you would be happier doing.
Walter