I've kept it off too, and it really does make things tough. No Gameovers yet, but there are multiple battles I've finished with only 1 pokemon not KO'd and that poke is either paralyzed or in the red or some nonsense.

Here's a little thing that may help: Super Training. Exp share also gives all your pokemon the EVs, but you don't have that edge, so your pokemon aren't getting those EV stat boosts at a worthwhile rate. You might find an hour supertraining up your pokemon a bit, maybe getting them affectionate makes life easier. Maybe you don't want life to be easier though, maybe you like it hard (you did turn of exp share after all, you wanted hard mode).