I Found Out Recently I'm Very Anemic. My Doctor Prescribed

I found out recently I'm very anemic. My doctor prescribed 65 mg iron (325 mg ferrous sulfate) 3 times a day. I started taking it yesterday and was able to take two doses and took one this morning. Around noon I suffered a bout of diarrhea and vomiting. I'd had several diarrhea instances but didn't vomit again till about an hour ago. Would this be from the high dose iron or is it more likely a bug? I've taken iron before without issue but not at this dosage.