IPhone 7 can’t hear caller and caller can’t hear me

I tried to do the new update (iOS 11.2 I believe) on my iPhone 7. that was when it basically went kaput. it first wouldn't go to "sleep" when I would hold it to my ear to talk. so I did a hard reset on it. wouldn't come back on until it died and I plugged it in the next day. made a call to my husband, he couldn't hear me and I couldn't hear him, even when it was on speaker. so I did a hare reset again; same thing. it wouldn't come back on for a few hours. I've connected it to iTunes but it won't do anything that I haven't already tried.
NOW I can't hear any phone calls and they can't hear me even when it's on speaker. the volume works fine and music plays just fine as well. I tried to voice memo app but it won't even say its recording.
I don't want to have to do another hard reset on my phone and risk having it not come back on permanently.
what do I do from here?