Can someone explain how my World Position can change...

Bonic-Stats has given me 2 accounts... don't ask why... one account is for my active projects... and the other is for my retired projects...

But when I look ar the stats for my retired account, it says I keep dropping position points every day... how is that possible? everyone I am competing against is in the same position.

No not everyone or even the most are not in your position.
They are still using the same e-mail address in the active projects as they had in the retired projects.
So they have both types of projects still combined. That's your discrepancy.

Since you are already having a BOINCstats account for 4½ years you have the possibility to combine them by syncing both stats.
This is only for the statistics on BOINCstats, not for other statistics sites.

Have a look in your BAM! menu in menu-part 'BOINCstats' at the item Sync retired projects.