If Tyrese was half the size of Carol, there wouldn't have been any problem.
The infected had to dealt to.
(The only thing Carol did wrong was acting expediently, and not taking it to the group. There was a line in House a while back: "Don't be an idiot! If all infected persons presented symptoms, then all illness would have cured when we were still cavemen just by smashing the guy with the runny nose's head in with a rock!)
Dealt to could mean cure, could mean isolate, and could mean Euthanize.
Why did Hershel wait till people were already dead till they sent off an expedition to the Vet School?
Anyone believing that those two infected carriers in the prison were still living people with souls and not merciless killers, was like Lizzie believing that Walkers are still people with souls and feelings.
(Well it's kinda obvious from that perspective.)
But frankly, if that's the case, if this story is a fractured do-over to educate Tyrese into not being a dick about shit he can't control, you do have to ask, how dumb is he that adorable little blonde girls have to die every time he has to learn anything?
What sized golden mountain of corpses was stacked when L'll Tyrese was learning his times tables?
Carol comitting suicide?
I doubt that there are any idiots into suicide left. Sure if you're cornered and there's no way out, but to have a "fuck it" moment because you're hopeless, bored or tired, and stick a gun in your mouth, all the survivors that are going to do that have probably already done that and good riddance.
Remember the moron from two weeks back still dangling on the same noose for two years?
Of course Carol's mind has broken a few times and what fixed it self up in the place of each previous Carol was probably a little harder than the last.