ROMEO (to Juliet in the tomb)
I still will stay with thee
And never from this palace of dim night
Depart again. Here, here will I remain
With worms that are thy chambermaids. O, here
Will I set up my everlasting rest
And shake the yoke of inauspicious stars
From this world-wearied flesh!
(5.3.106-112)
Poor, dumb Romeo. He's convinced that he'll one-up the "stars" by killing himself, thus ensuring that he spends 4EVA with Juliet. But, in fact, taking fate into his own hands just means he ends up killing himself for nothing—and ensuring that Juliet dies for hear. If you're looking for textual evidence that Romeo brings about his own "fate" (by making a decision (of his own free will) to kill himself, then this is the passage for you.
Quote 35
ROMEO
I have been feasting with mine enemy,
Where on a sudden one hath wounded me
That's by me wounded. Both our remedies
Within thy help and holy physic lies:
(2.3.53-56)
When Friar Laurence asks Romeo where he's been, Romeo, who has been hanging out with Juliet, uses a familiar metaphor to describe how he and Juliet fell in love. 16th century lovers were always running around saying things like "Oh, I've been wounded" to describe their passion. (You can learn more about this by going to "Quotes" for "Art and Culture, where we talk about the conventions of love poetry.)
What's interesting about this passage is the way Romeo suggests that marriage is the thing that can heal or "remed[y]"a love "wound." When he says that Friar Laurence (who just so happens to dabble in herbal medicine) can use his "holy physic [medicine]" to heal him, he means that he wants Friar Laurence to perform the marriage ceremony.
Quote 36
ROMEO
Tybalt, the reason that I have to love thee
Doth much excuse the appertaining rage
To such a greeting. Villain am I none.
Therefore farewell. I see thou know'st me not.
TYBALT
Boy, this shall not excuse the injuries
That thou hast done me. Therefore turn and draw.
ROMEO
I do protest I never injured thee
But love thee better than thou canst devise
Till thou shalt know the reason of my love.
And so, good Capulet, which name I tender
As dearly as my own, be satisfied. (3.1.63-73)
When Tybalt challenges Romeo to a duel, Romeo refuses to fight because he's secretly married to Tybalt's cousin, Juliet. Here, it seems that Romeo's love for his new wife is the most important thing to him. But, after Tybalt kills Romeo's best friend later in the scene, all bets are off.