@youspacewalnut - Having to assume here that you have no viable save from before this trip to Uni to revert to in order to replay everything leading up to the issue including building up the BF relationship? This is a problem with only having one save plus the automatically made one backup save that TS3 provides. It's really much better to always (or frequently) use Save As and change the name of each save a bit each time such as by adding a number or date to the end. That way we always have 4, 6, or however many saves in the past that we want in case something like this should go wrong. Eventually we will have more than we want and the older saves can be overwritten, deleted, or once in a while we might shift one to a storage location outside of the user game folder for archiving purposes.
I have easily over 150 saves of my nine year old ongoing game stored in various places. That's admittedly a bit extreme, but there is no way that something horrible can happen to my present day game session that could ruin everything I've done with it since 2011 and it's fun to be able to look something up about my sims as they existed generations ago when the mood strikes. Plus I get to see how horrible a designer I was when I was new to the game myself, which can also be fun but in a different way. :)
On the mods question, the NRaas mods in particular would be Overwatch, ErrorTrap, and Traveler, then also MasterController to give us user-initiated commands to help find missing sims if they don't show up on their own. The first three are designed to be in place before world travel begins though in order to provide the protections that they do, not added mid-stream, but you have nothing to lose by adding them in now from whatever your earliest reachable point is in gameplay. And should the unthinkable happen and you don't like the mods, they are all easily removable.
