Enter the Vortex.
For the first few minutes, I get that feeling too 
Nah, all I feel is a sense of wonder and the need for humanity to get on out there.
When I behold, upon the night’s starred face, huge cloudy symbols of a high romance, and think that I may never live to trace their shadows with the magic hand of chance…then on the shore of the wide world, I stand alone and think 'til love and fame to nothingness do sink.
Pretty cool. Pretty cool. 
When I used to walk our dog late at night (as a kid), I’d look up at the vast night sky over the houses and think “Wow, that’s big” So, no, I never got frightened. Just a sense of awe looking up while waiting for Laddie to poop.
Yeah, but that means that, no matter how badly you screw things up, it won’t affect the universe as a whole. That’s a very comforting thought sometimes, at least to me…
it just tells me what I always knew…I’m a really terrific and great guy
Yes, I have. I even admit that sometimes, pictures of space (especially ones of planets in our solar system) freak me out a bit - though I’m OK watching science fiction movies (must be the “fiction” part).
Now, the part about “what if love blah blah blah” is where you lost me. Sorry.
No reason not to try, though.
For the ultimate fear of the universe, try reading Asimov’s Nightfall.
Personally, I always thought that being able to pick out the constellations was an awfully comforting feeling. And I like looking up at the moon and mentally shifting the spots into the various shapes (Old man, Rabbit and Cabbages, Crab, etc).
Although I am awed by the night sky, it’s more a relief to feel that I’m not really that important in the whole scheme of things.
I find the night sky incredibly peaceful. I love to sit in a hot tub on a cold winter’s night and stare at it.
Space in general freaks me out. I was obsessed with the solar system in second or third grade, but sometime after that, the idea started to be scary. I am so ridiculously unimportant and little.
Yeah, but after he does make sure to bring your focus back down to Earth.
If you face the east, and look at the North star, then lean sloooowly backwards, you can eventually see Uranus, if you are limber enough.
Ah, so that explains why so many people walking their dogs fail to pick up their dog doo, they are so awed by the night sky they don’t even realize that their puppy has pooped.
If anybody cares, I was quoting from (rendering in prose, actually) John Keats’ sonnet “When I have fears that I may cease to be”–don’t want anyone to think I’m claiming that (though I wish I cold get the credit for it.) Or did you think I wrote in in rhyming, iambic prose?
Well, actually … 
I believe the term you are looking for is “Astrophobia”