Various iPhone Issues

I have an iPhone XS and I have been having a few issues. A few days ago my phone would randomly freeze up and crash. I figured nothing was wrong because this has happened before so I thought nothing of it. Today, I have not been able to receive phone calls (they will appear as a missed call notification but that's the first I will see of them). Tonight, my phone got stuck on one app and it won't let me leave it. I can use the app in it's entirety but I can't swipe up to leave and I can't even click on notifications to leave the app. If I try to do a hard reset I will feel my phone buzz but the reset screen won't show up and my phone won't restart no matter how long I hold the buttons. I tried to sync my phone to my mac to do a backup and reset my phone but when I click the "trust" button on my phone it fails on my computer's end. I'm not sure what to do at this point so if anyone has suggestions please let me know.