Horizontal Sticky Scroll Stacking

I am trying to stack the left hand vertical headers as you scroll through them horizontally. So at the last slide it should have ‘Our Mission’ followed by ‘Reccomendation’ etc all stacked. How can I do this with sideways scrolling? I have an example below that which works for vertical scrolling.

Second question, how do I ‘push’ between these sections, so if you begin to scroll from one to the other it will automatically move to the next full slide?


Here is my site Read-Only: LINK
(how to share your site Read-Only link)