The Time Machine
How we cite our quotes:
I was seized with a panic fear. [...] My fear grew to frenzy. (3.11)
The Time Traveller may be a pretty good scientist, but he's no Mr. Spock – he can be a very emotional person. Sometimes he can be excited or amazed, but he spends a lot of the time in the future being afraid. Often that fear ends up making him run around and do things that aren't very productive. (He does, however, seem to get a lot of exercise in the future.)
At once, like a lash across the face, came the possibility of losing my own age, of being left helpless in this strange new world. The bare thought of it was an actual physical sensation. I could feel it grip me at the throat and stop my breathing. (5.4)
In The Time Machine, fear isn't abstract. It really feels here like the Time Traveller is being attacked by a fearful thought. This is interesting in that one of the sources of his fear – the Morlocks – do physically attack him. However, that doesn't mean the Time Traveller would rather live in a world without fear.
That is what dismayed me: the sense of some hitherto unsuspected power, through whose intervention my invention had vanished. (5.6)
One of the primal fears in The Time Machine is fear of the unknown. So while the Time Traveller is traveling into the future, he starts to worry about what he'll find. And now that he knows that there is something (or someone) else in the world, he'll worry about that. He always finds something to fear.