Hi I Have Been Having Palpitations After Eating And Low

Hi I have been having palpitations after eating and low ish blood sugar (3.7) when tested. Then Yesterday I Was sick and have been sick 3 times but I couldn't go even to pass wind. I became bloated and bloated and my stomach kept cramping and making noises then I had diahorrea from hours between 7pm and 2am yesterday. The diahorrea has stopped know but I am really hungry, what is happening to me?