Deleted Hospital

NinaTheGreek_95 Afaik, there is no way to get to the Hospital (or Police Station, Lab or Acting Studio) except through gameplay.  And since you're already tried both ways to get there and didn't get to the lot, you're out of luck.  So, the only thing you can do is revert back to a save from before you saved last.  So, go to the main menu, use the load button, mouse over to the right near where the play and delete buttons are to get the recover button to show up.  Click that and see what comes up.  If any earlier versions of the save show up, chose the top one.  Then load that save and play enough to find out if you can get to the hospital again.  If you can, you're good to go.  If you can't, exit back to the main menu, use the recover button and choose the next save down and recover that.  Check again.  Rinse and repeat until you either find a save that has the hospital back or you have checked them all.  If you have any other saves, you can try those too.  If you don't find a save that has a hospital, then sadly, it's new save time.

If you want to save all your played or custom lots, all you need to do is to save them to your library.  Start a new game and then place the lots from your Library.  Same goes for sims if you want to save them too.    

Hope this helps.