Panicking! Might have caught a bug for the first time in years??

I woke up today not feeling great. By mid-day I was dizzy, nauseous, hot, and having diarrhea. I have chronic GI issues so nausea and diarrhea aren’t uncommon for me, but this time it feels different. I didn’t eat anything besides breakfast until now. I basically slept all day but then I woke up feeling slightly better and decided to try some toast and white rice. It stayed in me for approximately 10 minutes before coming out the other end. At this point I can’t even take sips of water without feeling sick. My stomach is cramping and I’m scared to go to sleep in case I wake up throwing up. I already took my prescription nausea med phenergan and it didn’t do much. I have zofran too but I’m not really supposed to take it because of heart arrhythmias. But I guess desperate times call for desperate measures. I’m actually so terrified. I haven’t been sick in YEARS. When I’m sick I feel like I can’t even relax, I just lay there and go into a panic spiral. I’m not sure what to do and I don’t know if I should go to sleep because I don’t want to wake up getting sick. I feel like it’s been so long since I’ve been sick that I don’t even know how to handle it anymore.