Am I overreacting?

Im not sure if this detail matters but I started keto on monday so today would be day 3. This morning I woke up so tired and dizzy. I woke up a few times during the night and my heart was pounding out of my chest. I made breakfast for my son and I and I was sweating and it wasn't even hot. Then my left lower arm started to feel weird. It feels numb and tight and weak at the same time. I'm scared I might have a heart attack. Could this be a heart attack or soon to he heart attack ?