Broke function.php with GA track code

generally, try using FTP to upload an unedited copy of functions.php into your theme;

http://codex.ww.wp.xz.cn/FTP_Clients

alternatively, use FTP to rename the folder name of your theme to something else; this should activate the default theme Twenty Fifteen, and allow you back into the dashboard. you can then repair the broken file(s) in your theme, rename the theme’s folder back to original, and re-activate the theme.

if you need help with finding or installing this unedited functions.php, please contact the developer of your theme for support; http://codex.ww.wp.xz.cn/Forum_Welcome#Commercial_Products

ps:
try using a plugin for the GA code – https://ww.wp.xz.cn/plugins/search.php?q=google+analytics+code