30? That is low, I have hit that a few time but not fainted.
But you use a blood testing kit so you can monitor your levels?
Most of us do a ratio of 10 grams of carbs for one unit of insulin, so say you eat a bun with 30grms of carb then you would inject 3 units of insulin which...should...theoretically keep you on the straight and narrow, however that is just an example and we are all different in the way we react to insulin and hypos.
Your medical team should be able to advice you how to go about this plus there is lots of info online about it. But be a little wary as I think that here in the UK the amount of carbs in food displayed on packages might be different from where you are.
If you have had a bad hypo like that and then eating regular food plus add in the glygocon dump from the liver, I would expect you to climb, I would, but if it was me I would be checking my blood sugar levels every 30mins to 1 hour and if it started to get to an unaceptable level I would correct but only with small amounts of insulin.
That is how I do it and please bear in mind I am not medically qualified, just been a T1D a long time
You shouldn't be scared to eat, it is just a balance to get the right combo of insulin and the food intake you have. It is learning curve and takes some experimenting to get it to click.
Even after all the time I have had this I am still learning and still here and I have had this for over 50 years