Keto flu usually appears after 24-48 hours and last 2-5 days or so. It's odd to me that you are getting these symptoms now.
It's suggests you weren't low carb enough before or it's unrelated to the diet. In my experience you start feeling better and better after 10-14 days.
One thing to check is the keto 'junk food' that is processed food that claims to be keto. Some versions of keto have you only counting net carbs and lots of 'keto' food go with this rather then total carbs. Might be worth checking your bread rolls, tbh it's best to avoid this kind of food in the first two weeks and introduce later to allow your body to properly adjust.
The first time I ketoed it was recommended that you eat under 20g total carbs, not net carbs. It might be that you simply weren't eating a low enough level and and as a result your body has taken this long to properly deplete your glucose reserves.
If it is indeed keto flu then good and bad news. Bad news, you will feel crap for a couple of days. Drink lots, take painkillers, rest, treat it like a cold,.
Good news, you will actually get into ketosis and feel great.