Severe stomach pain after accidentally almost OVerdosing myself

Last night I posted about how I accidently got myself high. I know I sound like an idiot but I had no idea that what I took could do that. I was so sick last night, couldn't breathe through my nose constant sneezing, pressure in my head. I took DayQuil and then like an idiot 20 minutes later I took 1200 mg maximum strength mucinex.,
My boyfriend was like are you sure you should be taking all of this? I was like yeah? I'm fine. About 30 minutes later I was not fine, I felt like I had just taken 10 shots of vodka. The room was spinning and I couldn't walk. So of course I started freaking out and called poison control and told them exactly what I took and they told me to eat and drink  well and that I would sleep it off. I slept until 3pm today. And now my stomach hurts so damn bad-probably due to poisoning my damn self but I can't even eat. I also feel hungover and like I'm going to puke. Is this all normal for what to expect when you do something this stupid?