Is this normal?

So recently I had food poison from red meat around sunday 12 in the afternoon. I had constant diarrhea and my stomach swelled up, bloating. I took some medicine. I didn't eat that much for the past 2 days, but I kept gaining the weight and my stomach pained even more. I went to the hospital yesterday and they injected my wrist putting these clear liquid in me and I stayed put around for 4 hours. I felt better but still bloated. That night I had diarrhea again for 2 hours. I weighed myself and the scale went higher. I'm so worried I don't know what's happening to me, I barely ate anything. Today I had vegetable rice soup with half of a corn. For lunch I had vegetable soup again and the other half of the corn with some tofu. I don't eat dinner but I knew my diet would worsen if I skipped it so I had 40 tiny grapes with a cup of unsweetened almond milk. That's 470 calories in total today, I weighed myself and for the past 3 to 4 days I gained 3 kg?? Please tell me what's going on, I'm so concerned