Sonnet 14 is structured like a Petrarchan sonnet, which is to say that it's split into two sections: the octave (the first eight lines) and the sestet (the last six lines). The octave's rhyme scheme is abbaabba, and the sestet's is cdcdcd. In Petrarchan sonnets, broadly speaking, the octave poses the problem the sonnet is going to deal with, and the sestet suggests the resolution.
So right away, we know that "wrought" and "unwrought" are going to be a big deal, because they bridge the gap between line 8 and line 9—they mark the transition from the octave to the sestet. And it's clear the speaker's thought process is evolving: in the octave, she lists positive reasons her lover might love her (her smile, her looks, her gentle speaking, the way she thinks), but in the sestet, she focuses on darker reasons (because he pities her). It's clear that she's getting more worried and depressed as the poem goes on (in fact, she acknowledges this explicitly in line 10 by talking about tears on her cheeks). And the trigger that leads her to these darker thoughts is the switch from "wrought" to "unwrought."
If you notice, the speaker never acknowledges that her partner might stop loving her in the octave. She dances around the topic—why else would she be talking about loving her for the wrong reasons?—but the first time she explicitly says that she's scared that her partner might stop loving her is when she says "love, so wrought / may be unwrought so." It's the first time she allows herself to fully come to terms with her own fear.
The choice of the word "wrought" is also significant because it hints at the way she thinks relationships get formed. When something is "wrought," it's made. "Wrought" is often associated with metalwork—the blacksmith wrought the sword. Think about that process: he subjects a chunk of metal to extreme heat so it's malleable, then he whacks it with a hammer over and over. If that's the way to fall in love, I'll pass.
"Wrought" can also mean, more generally, "made by using your skills." The idea you should be getting is that it's a process that takes hard work and craftiness. Now apply that to the process of falling in love. It seems kind of cold and calculating, doesn't it? To my mind, if someone "wrought" love, it seems like they were trying too hard—they worked to manufacture it, rather than letting it happen naturally. Clearly, the speaker is suspicious of love that comes about that way. Ultimately, "wrought" love is the villain in this poem, the antagonist to the speaker's desired "love for love's sake."
As a little side note, that phrase, "so wrought / may be unwrought so," is an example of a rhetorical device called chiasmus. Chiasmus is when you repeat a phrase in reverse word order and structure: so wrought, wrought so. (Shakespeare loved using chiasmus, and it shows up in a lot of great speeches.) It can be a very powerful way to mark a sharp divide or suggest a concept needs to be rethought. And that's exactly what the speaker in Sonnet 14 fears most. After all, it's life-shattering when your partner decides he doesn't love you anymore.