Create your animation in After Effects, render a movie using the Lossless preset (or Lossless With Alpha if you need transparency) in the Output Module in the Render Cue, then open the movie in Photoshop and export it as an animated gif. It would also be a good idea to remove any duplicate frames in your animated GIF (12 seconds is an eternity) and adjust the timing of the remaining frames so the timing works as you want it to work and you do not have any repeated frames. This can reduce the file size by 80% or more in a lot of projects. You can have one frame last 20 seconds if you like, then 10 frames of a transition, then another 20 seconds then another transition. Now you have a 45-second animated gif that has less than 100 frames. You can't do that in AE even if you buy 3rd party plug-ins. AE is just plain lousy at creating animated gifs internally. In Photoshop you have a ton of options for reducing the color depth to 256 colors and controlling opacity.
One more thing. In the future just drag your screenshots to the forum. It's a lot easier than posting them to another site and creating a link, and it saves us a bunch of time.
Thank you so much! It works! I knew that 12 seconds was long, but it was a very simple 2d animation with very little color, so thought it would work out. But thanks a lot.
I found a way to make any gif look great. I made the gif look the way I wanted, then I saved each frame as a seperate png. I then opened Microsoft PowerPoint and made slides that used my new png frames as backgrounds. Then I went to export and selected animated gif. I chose the resolution and timing, which took a couple tries, and there you go. No grainy, pixely, jittery dots, just a good clean gif.