Help With Sounding Polite.

I’m in a Japanese language class and we were doing diolouge practice. Me and another student were volunteered to practice the diolouge in front of the class. I tried to make sure that my speech while reading the script the teacher gave us was as proper and natural sounding as I could get. After class however one of the students told me that my speech sounded too “anime” and that it was very rude. This horrified me because I definitely wasn’t trying to sound like that and I absolutely know that anime speech is far from proper and shouldn’t be used. I do have a deep voice and he seemed to take special issue with how I pronounced どうも in the conversation. We were reading from a script so I wasn’t using any weird language, his main problem seemed to be how deep I said どうも (I think). The only other problem I can think of that he might of meant was the slight Japanese accent I use while speaking Japanese. This whole interaction has left me very worried as I’m going to Japan in May and my worst fear would be offending anyone with how I talk. My teacher didn’t say anything and she’s a native speaker however the guy who corrected me has a Japanese wife so I assume he knows what he’s talking about so I’m very unsure if I actually did anything wrong or not and if I did I want to correct it as soon as possible. Should I try and talk higher than my natural voice? Should I not use an accent? My understanding was that most of being polite was the words you use, I didn’t know having a deep voice and an accent sounded too “anime”. I really don’t want to sound rude, so any advice is greatly appreciated.