Elayne, I completely agree with your view stated this and similar ways: "For me it is more like I have pleasures _in spite of_ unavoidable pains of the past or present, not _because of_ these pains. "
The part where I am not sure is that saying that we only have pleasure because of the existence of pain (and therefore we need pain) might not be the only way to read what Wright is saying. (Although I agree that it seems she is saying that)
Where I am thinking there may be validity is to ask a similar question:
Does matter exist because there is void? Does void exist because there is matter? It may be that Wright senses that Epicurus was saying that reality is the way it is because of Nature and that we should be grateful to Nature that reality is the way it is (various sayings I think would support that including the one to the effect of being grateful that what is good is easy to get and what is bad is not ....... -- I need the exact translation here.
So it might be possible that Wright is extrapolating from that.
Here it is: