I think there are lots of drugs references here. The song is probably about someone giving them up or being made to give them up by a loved one. 'Can't get full' implys 'the munchies' and 'take my shakes' withdrawal. Also if in the song 'The Good Ones' little sisters's eyes are so wide because she's on drugs then 'my eyes are spiky and small' may mean the opposite. However some drugs would constrict your pupils so the whole song could be about the effects of taking drugs taking rather than withdrawal from them.
I think there are lots of drugs references here. The song is probably about someone giving them up or being made to give them up by a loved one. 'Can't get full' implys 'the munchies' and 'take my shakes' withdrawal. Also if in the song 'The Good Ones' little sisters's eyes are so wide because she's on drugs then 'my eyes are spiky and small' may mean the opposite. However some drugs would constrict your pupils so the whole song could be about the effects of taking drugs taking rather than withdrawal from them.