Please try the following options for speeding up the theme.
- Go to Dashboard / Media and Remove the unwanted/unused images. OR you can use third party plugin for removing unused images – Image CleanUp
- Go to Dashboard / Plugins and delete unused plugins, etc.
- Optimize all the images that you have used in the theme.
Ex: Sumsh It
- Use some cache plugins like Wp super cache
- Get a good hosting server for your website.