Converting a .webm 2MB file to GIF results in 150MB file. Any advice?

Hi,

So I managed to get a hold of the plugin to be able to use .webm files in Adobe and wanted to convert a .webm file at 2MB to "Animated GIF" but it ends up being 150MB. Tried to tweak the settings, but didn't help much. Any solutions? Gif file is too big in other words

Thanks in advance.