So then does Gen 2:18 suggest that women are merely helpers for men?

Not even the very verse in question, let alone the whole Bible, says anything so demeaning. God regretted that Adam was alone, so this person was to be good company for Adam—and then, since company is good only if it is reciprocal, that entails that he would have to be good company for her. More to the point, obviously, since woman is described as having many other functions, we must not assume that the Bible is suggesting that the whole Biblical role of women is exhausted by “companion helper,” which sounds something like a slave.