Hey 5 pounds can definitely make a difference (congrats on the weight loss btw!) If i lose 5 pounds it really helps my numbers. Was it a rapid weight loss?
In either case if u’ve been like this for three days already I would adjust the basal rate. Maybe speak to your doc.
About the protein thing..i dont find that it helps. If you over-insulinate then u’ll fall low no matter what- just my opinion.