Water melon toxic when it comes to excessive

Eating water melon and banana called lakatan can upset ur stomach easily it happens to me few days ago when I had a visitor and when we missed eating proteins and I never maybe missed washing my hands properly before and after eating
That’s the time that when I ate and consumed those high potassium fruits became my angony I try to be weak dehydrated and don’t like to eat my body began to drop and my stomach is so aching that I almost can’t endure the pain I try to rest for a while but I can’t sleep properly and it hurts everytime when u breathe deeply from your lungs and almost 5 times u always poo and uses toilet where there is a shitty liquid coming from your pants this is so embarrassing
Right now after 3 days of suffering I’m feeling better I put an ointment in my tummy and drink plenty of water and do eating bread apples banana tundan and water  and also pray and drink medication controlly like loperamide and buschopan with moderation