When i get low blood sugar I get jittery and shaky and weak feeling.
But my anxiety attacks feel somewhat similar to low blood sugar and i think that my low blood sugar actually contributes to my anxiety attacks.
As soon as I eat a carboyhydrate-high food I get sleepy, dopey, my eyes get glazed.
You could get your sugar levels checked maybe, to find out for sure. Even get a tester and prick and test when you feel like that.. see what it reads.