I just bought Skyrim SE and Skyrim AE (Stand alone, not upgrade).
In the library I just see Skyrim SE with a DLC upgrade...

It seems I got the same as Skyrim SE and AE upgrade for 150% of the price.
Did I just get ripped off?

Did you get a gift code for SE in your mailbox? AE is just SE + AE upgrade. I'd double-check what you received vs what you paid and contact support if there's a mistake.

To clarify, that DLC in your library is the paid Anniversary Edition content (there's a little bit included for free in the base Special Edition, too). So, no, you got what you paid for. Though it appears you didn't ascertain what you'd be paying for before you paid for it. ;P

Alright, that cleared it up.

Thanks for the replies.