I think we need a bit more information before we can help you
When you say your numbers go up & down like a roller coaster what’s the numbers? is there big rises & drops? Are you using. CGM or finger prick to test? If your using a finger prick how often are you testing
BG aren’t a static thing they fluctuate quite normally, sometimes within 5 minutes. What are you expecting to feel? Are you below 4 and not feeling the hypo? Or are you high and expecting to feel rough? Are you on any medication for your diabetes?
Sorry for all the questions but the more info the better