I'm having a exact same trouble and this is extremely frustrating! :disappointed:

When I was studying for the GRE, my tutor told me not to move forward without fully comprehending the first paragraph. The first paragraph often provides a bird-eye-view and enables you to anticipate many things about the entire passage. (subject matter, the main point, direction of the discussion, tone, etc.) It might be helpful to read the first paragraph and guess how things will unfold in the rest of the passage. For me, it really helped!