Girls, how do you properly alternate breast feeding during each meal? …

Girls, how do you properly alternate breast feeding during each meal? It seems like one feeding I'm not eating completely, and over a month I ate a couple of times per feeding from both sides. But more milk comes in on the left side. Woke up half an hour with pain that it would burst, squeezed a little and woke up my daughter to feed her so she could help. The right side is noticeably softer, now should I give the left or the right after feeding?