I used the JetPack Custom CSS Editor to customize the appearance of the site without the need to create a child theme or worry about theme updates overwriting my customizations. So, deactivating the plugin simply removed the customizations.
Immediately, I tried reactivating the plugin but couldn't get it to work. It failed to connect to wordpress.com after reactivation. Hence, I couldn't access the Custom CSS Editor. I searched google to see if I can access it via CPanel but read somewhere that I can't except I browse through my database.
Instead of going through that stress, I tried putting JetPack into development mode using the Unplug JetPack plugin and guess what, it worked! All Customizations were restored!
While in the development mode, I was able to access the JetPack "Edit CSS" via "Appearance". I copied the custom css, added it directly to my theme file and also saved it to my dropbox as backup.