I guess the meaning is slightly different. Compare: "I bought myself a shirt" and "I bought a shirt myself". The first one means this shirt is for you, the second one means you bought it without anyone's help.
When you say "You have earned it", in English it is implied that you "got yourself some money by working". In Spanish, however, it seems that you have to use a reflexive verb.
I think basically, yes. "You won yourself it" is the way to think of the sentence. Then, just put it into good English. "You have won/gained it."
English does not have reflexive verbs in the way Spanish does.
And yes, I believe that "you yourself have won it" (or "you have won it yourself"). would be translated as: "Tú mismo lo has ganado." (or "lo has ganado tú mismo.")
Could a native Spanish speaker confirm or correct my translation attempt?
While thinking of the "te" as meaning "yourself" is a good way to help learn how to approach reflexive pronouns, they are not always translated directly that way.
Often, a reflexive pronoun will change the entire meaning of the verb.
The reflexive form ganarse usually means "to deserve" or otherwise suggests extraordinary effort. It also is frequently used to refer to those who win a lottery or drawing. https://www.thoughtco.com/how-to-use-ganar-3079801
http://dictionary.reverso.net/spanish-english/ganarse http://dictionary.reverso.net/english-spanish/deserve http://dictionary.reverso.net/spanish-english/ganar http://context.reverso.net/translation/spanish-english/te+lo+has+ganado I think that without context you should use the most common meaning as there is another verb for "deserve". It really only means "you have deserved it" in the sense that "you have earned it". I commonly say "you deserve it." in present tense but am more likely to say "you have earned it." in the present perfect. I think you either deserve it or not, but all the tenses apply to earn. I mean "You have deserved it." what until now? Suddenly you might not deserve it any more? You deserved it sounds like you never had to do anything to deserve it and that would be outside the purview of this verb in which you deserve it because you earned it. What do you think?