I am confused by how time is discussed in Chinese,
下一次/下次 (next time) 


Imagine the present time is the beginning of a list. When you go further down the list, the further into the future you will be at.  


上一次/上次 (last time) 


Imagine you are currently in the middle of a list. When you look up the order on the list, the further you go up, the further you got back in the past.


之後/以後/後 (after)


Imagine the present time is on the first page of a book, the more you turn the pages, the further you will get to the future - in the back of the book. 

For Example: " 第二次世界大戰後 " (after WWII) . 

"第二次世界大戰" was the reference point of a time line (it is on the first page). Every thing that followed (future),  are all in the back of the book.


之前/以前/前 (before) 


'前' here doesn't mean 'forward'. It means 'previous'. As in '前男友' (ex-boyfriend), '前政府' (previous government). Therefore. '以前' means 'from the previous' = 'before'. 

*前(in front/forward) can also mean 'future'. Imagine the present time is a line you stand on.  '向前看' (look in front) is the future. See similar terms like: 


'前途' (road in front = future ahead) 
'前景' (scene in front = future prospect)