I think your understanding is spot on :)
In terms of whether it’s a ‘correct’ translation (if such a thing does exist), you should think about the purpose of the translation. I know you said you were doing this for fun, but I think it’s worthwhile to think about it in any case!
(Without going into it, there are other approaches/paradigms/theories of translation, but I personally think translating for purpose makes a great deal of sense. Take a look at Skopos Theory, for example, if you are interested to learn more!)
The major question in this case, apart from who your audience is, would be:
Is this to be printed (e.g. in a lyrics booklet accompanying a CD), or to be sung in translation?
If the former, your suggestion is probably good as is.
If the latter, you need to consider how the text fits the music, e.g. stress/vowel length/number of syllables in the phrase etc. Something like:
“You should be able to-oo return / to your o-old se-elf”
might for instance fit the music better than your original suggestion, as the number of syllables in your translation seems to me to be too few to match that musical phrase.
Of course, there will be many valid and effective translations for a given purpose, and other translations which are valid for other purposes (just a recipe in a children’s cookery book is different from one in a typical cookery books, which is again different from recipe instructions for those training in the catering industry), so have fun with it, but also be clear on your purpose to get the most out of it. That there is so much scope is what makes ‘practical’ / ‘advanced’ / ‘stylistic’ translation so very challenging and interesting! :)