Technically, 4.3 is not a hypo. I think there is something called a "false hypo".
However, if your body is used to a high BG, it will feel like one.
Over time, as you train your body to become familiar with the lower BG, you will feel ok at 4.3.
In the meantime, don't overdo your hypo treatment - you need your body to become comfortable at this level.