How can I get TS2?

Best bet at this point is look on Ebay and buy second hand copies. The bad thing about that though is they are pricey (I've seen the complete collection for 100+ dollars), and a lot of times a disc or two is missing, and to top it off if you are on, say Windows 10, the disc version of The Sims 2 you system and settings can possibly require some tweaking to get to work. Honestly, unless you are desperate I would just wait. I'm sure some day Origin will re-release the games. No game as popular or financing successful remains 'out of print' forever. It might take 5+ years but I would bet my bottom dollar TS2 will rear its beautiful head once more on a digital format with full compatibility for the (then) current windows.