no longer have access to my expansion packs

A couple years ago I purchased all kinds of expansion packs, and of course I used them a lot. I stopped playing for a while and just got back into it, but have no access to my expansion packs. My old saves prove I had all different expansion packs but I can't load those games because it's saying they require the packs that were used. So what I'm understanding is it wants me to pay to get all my expansion packs again? If that's the case I don't think that's right or fair at all. I would love to be able to get all of it back without paying again because I spent a lot of money on them.