I agree that you situation is a bit different from mine, and if you are only taking 2 units per day then you are taking very low doses, what have your readings been like?
How much do your sugars change per unit of insulin ? Is this going to be your last meal of the day, or will you be eating again later that night ?
Do you have the ability to give half units? like maybe take 0.5 units before the meal and then your 2 later, just to keep you from going really high.. This isn't advice, just brainstorming here haha