Oh no I am so very sorry
There must have been something that just gave out suddenly. You never can tell with such a young hamster what has happened
When you feel able you must let the breeder know because this is important so that they can check out the lines and try and make sure there is nothing that needs investigated. They will also be sorry to hear about this and will most likely want to help you fill the hamster shaped hole in your lives when you are ready.
Play well at the bridge Rupert x