Kitten afriad of new kitten

I adopted a male 3 month old kitten, when I first adopted him I was torn on whether I should get 1 or 2 cats, I walked away with just one but i ended up regretting it so I adopted a second kitten who is the same age about a month later.
   
My first kitten was very friendly and playful, he never seemed to want to calm down. The second kitten is also very friendly and playful but is a lot calmer. we introduced him to the new house and then to the kitten slowly and he relaxed very fast. but my first kitten is terrified of him. he doesn't even play anymore, the second kitten hasn't done anything to him to make him afraid of him. My first kitten runs and hisses and cowers into him self. Even after i put them in separate rooms for a break he was still hissing at his own shadow.
   
What can I do to get him not to be so afraid and to go back to his usual crazy self?
   

You have to let the whole thing play out. Cats often begin a relationship in a rocky manner, w/one having a fit, & one fine. This is Cat Politics. Cat politics can take 3 days, 3 wks or 3 months to play out, depending on the cats & the circumstances.
   
There's no blood, flying fur, or pitched deadly battles, so it's just a matter of the first kitten recovering from the shock of a new animal in the house. They're young, they can adapt. Given time, Kit2 will be able to break thru Kit1's haze of panic enough for Kit1 to realize that here's a built-in friend.
   
The problem we have is Kit1 has to get past the mental block & see Kit2 as a potential playmate. A suggestion:
   
Take 2 carriers. Pop one cat in each carrier. Place the carriers 3 feet apart & leave them to stare at each other for 1 1/2 to 2 hrs. (Much of a cat's time is spent considering a situation before acting.) Ignore hissing & such, it'll pass.
   
After 2 hrs, release cats & let everybody who cares to have any fits they want to.
   
Repeat this process 1-2 times a day, depending on your schedule at home.
   
After 4-5 days, move the carriers to 2 ft apart. Then 1 ft apart after another 5 days. Then 6 inches apart, at which point they'll be practically nose-to-nose.
   
This will keep Kit1 from running away in a panic, which is Kit1's first instinct. Since it's tiring being in a panic, Kit1 will eventually stop worrying so much & focus on the actual Kit2 as a kitty-person rather than a threat. They will have to smell each other & any grumbling & hissing will likely slowly fade out.
   
Do NOT be surprised if friendship does not blossom right away. This is normal with cats (dogs tend to cut to the chase a lot quicker). We're aiming at calming the "Run away" reaction in Kit1. Once that's conquered, subtle conversations will begin to take place that may only look like nose-touching. Or nose-swatting (also normal). Relations will inch forward, or they may move forward at a gallop. They could be not talking for weeks, then suddenly, all will be chummy. We can't tell.
   
With cats, we just have to let them take it at their own pace. Cats refuse to be rushed or forced.
   
Worry less. Pay equal attention to both cats. Feed them as close together as they're willing to be (here, it's Kit1 who'll object to proximity). Drag strings around the room, you might actually catch both of them. You'll have to play it by ear for some time.
   
Kit1 will regain his lively personality. He's too young to stay mad forever.

Thank you for your advice,
   
They seem to be doing much better now, they aren’t best friends yet but now I definitely have hopes that they will become good friends.
   
I was going to try the cat carrier idea but I don’t think I’m going to have to now, I started feeding them in the same room and moved them closer each meal since they seemed all right with it. The food definitely made my first kitten get courage to be near him, he loves to eat! The other thing that also helped was giving them treats, I would sit on the floor and slowly coax him to me while the other kitten was near me and give them both treats that seemed to help him not be so afraid of coming near the kitten.
   
I also have a small adult poodle mix, and she actually helped make them closer, she is a very friendly dog and both kittens are good friends with her, they both cuddle with her and play with her, and my first kitten got very interested when he noticed that the new kitten was playing with my dog. He would timidly go up to them but he wouldn’t really join them but it did give him the idea that they could play together.
   
So now only a few days later they will eat in the same bowl and they both will lie on me together, but they haven’t laid together on their own yet and they chase each other, I feel like its getting more playful then aggressive though, at first I felt like the chasing was very aggressive, especially on my first kittens part because he would growl and hiss but now he’s not hissing so much and they will stop playing and lay down to look at each other, so it seems like they are getting along a lot better.
   
Thanks again for your help, I have good feeling that their relationship will just keep improving.