How to create gif in After Effects thats stops at the end?

To efficiently create an animated GIF in After Effects, you need to set the composition's frame rate to no more than 15, then make sure that there are no duplicate frames next to each other. If you move some text in from the left for 1/2 second, then stop in the center for 3 seconds, then move off to the left in 1/2 second, you set a keyframe at frame 0, move to frame 7, and move the text to the center, then move to frame 8, and set another keyframe without moving the text, then move to frame 15 and move the text off-screen to the right. There is only one frame where the text layer is not moving. 

After you render your Animated Gif, open it in Photoshop, open the Motion workflow, scroll through the timeline to frame 8, then set the duration to 3 seconds. 

You now have an animation that lasts 4 seconds and only has 16 frames. You can also set the looping options and add additional frames and layers to create an optimized animated GIF.

File/Export/Save for Web Legacy and pick GIF. You can then optimize the color palette. There are only 256 total colors available in a GIF. Optimize transparency and even set the looping options. Ideally, an animated GIF (any animation for the web) should never have duplicate identical frames next to each other. When I used to create Animated Baner Ads for clients, I could have an animated GIF with transitions between 10 different slides that were only 110 frames long but played for more than a minute. 

There are many more efficient tools for creating animations for the web than After Effects. AE is just not well suited to that format. Anything you make for the web using After Effects should be optimized, and Photoshop or Adobe Animate are the right tools for that.

The workflow is terrible anyway and you simply can't control the frame duration. Render out an image sequence, import it into Photoshop's timeline and export your GIF from there or use one of the gigazillion other GIF converters out there, be it online services or respective function in standalone image viewers/ converters.

Mylenium