You wrote this, Lex? I’m impressed. Actually, I wish native-speaker songwriters would use such good grammar. “Show” doesn’t work. You showed her the life, whereas she saw / experienced / lived the life. “The life” doesn’t work well because it’s not definite (as far as I can tell). I’d just say “life”. It works however, with “this”, “that” (for the past tense), or perhaps “our”. “Sometimes we think we do our best” — I’d recommend the continuous aspect for the action verb: “Sometimes we think we’re doing our best.” “I’ll be best you had” doesn’t work. For the superlative, you need the definite article “the best (that) you(‘ve) ever had.” “That” is optional — leave it out unless you like it for the rhythm. Present perfect would be the choice in UK English, but the simple past is good for American. We can either say “all bad dreams” or “all of the bad dreams” (in the second option, the dreams are definite). The verb “make” at the beginning of the sentence seems wrong — it should be 3rd person singular since it’s governed by “the star” (not by “you”).

"I never wanted you to show this life" — I meant in a bad way, like when we were together she lived with some kind of lonely feeling inside (feel lonely, don't pay attention to her in other words). Is the verb "show" appropriate in this context?

Not sure what show this life means - but seems like something interesting moving through life ("the" is strange here) "This time I'll be best you had." something wrong here. This time I'll be the best you had. - as in past, all over This time I'll be the best you've had. - including now "Make all of bad dreams go away," "of" is unusual here. "Make all bad dreams go away," or "Make all of the bad dreams go away," Otherwise, all good.