Diclegis medication for nausea

So I was prescribed diclegis for nausea. I took it on an empty stomach as it said to do and I still didn’t feel any better , the nausea was still there 2 hours later , it never left. Then I became SO tired (it did say it can cause tiredness ) I ended up taking a nap middle of the day for 2 hours.

I don’t think I can take this medicine again if this is what it’s like. I’m curious if this is what it does or did I take it wrong? I took 2 tablets in the morning when I felt nauseous.