I've had spots like this with all three of myKids. Could be gas. Could be fast letdown. Could be slow letdown. Could be overtired... Sooooo many options. What works for me is cuddling my big in blanket that blocks out pretty much everything else. I rock and I hold his free hands. You also need to keep calm and heart rate normal. Honestly this will pass. If milk is too slow, the frequent latching will help cause a letdown and that will help. If your milk comes out too fast, lean back on the headboard of your bed when nursing. You really will be fine. Keep nursing and push through. 

When my mom was breastfeeding my older brother, she said he did this and the dr told her that he wasn't getting anything. I had my baby doing this so I started pumping and sure enough I only got 1.5oz on one side and 2oz on the other. Started pumping every time to be sure and it built up (until now when I've been too busy to pump) 

Mine did this sometimes. I would try a hunch of positions. Sometimes that's all it took, other times I had to walk around and bounce her a bit with a boob out and that helped or even bobbing a little on an exercise ball while nursing. But like a previous poster said, there are so many reasons why they can be fussy.