You can get symptoms of hypos at almost any number - its called a false hypo, due to it being lower then what your body is used too. However, you arent in any danger, you just feel like you are.
When I first got out of the hospital post diagnosis and DKA i was getting false lows and symptoms at anything below 7mmol/L for the first few days, and had to put up with it until i could get my average down and get used to living life back in the 4-6 range. I had spent months up around and higher then 10 so that drop was so large my body freaked out lol
After spending a couple days in the 4-6 range you likely wont get false hypos at 4.8 anymore, so keep it up!