Problems with Gameplay

I've been playing this for a little while now, and I keep getting errors that mess up my game play.

First, it had something to do with my child sim. I left the lot for my adult sim to go buy clothes, and coming back, the child sim completely disappeared. Even the name was changed to something like, "subject#..." whatever thing. The adults had memories of the chilf, in thr changed error name, but the child was nowhere. So, deleted that and started a new family. 

I made a single family household adult sim to keep things easy. After going to a few lots, eventually the game kept glitching the speed modes and it would permanently be sped to max. It wouldn't stop until my sim was back on their original lot. It was very annoying to go anywhere else. So, I thought. Let's repair this thing and retry in another neighborhood with a new family. 

Decided, let's try a university student this time. Everything was going great up until end of junior year when I was trying to get a meal, and my sim kept resetting itself. Therefore, never picking up the meal. I could do EVERYTHING ELSE except make food or eat food. Even on another lot. My sim would die of starvation no matter what. 

I thought, let's give this a final go. Un-installed. Reinstalled. Repaired. All that jazz. Played a university student. And my student couldn't go and take their final exam in their freshman year. Every time sent my sim to take the final exam, it kept sending them back after awhile still with the note, "final exam in progress" and then saying my sim missed it and lowering their GPA. 

I have no idea how to make this game playable. I don't use mods. I bought and used what EA gave me to make this play. It doesn't work. Please fix this.