iPhone 12 freezes and keeps restarting; do i have a virus?

The restarting thing started happening recently; last Sunday to be exact. I looked at my phone and saw that it restarted on its own and every time it finished I tried to open my phone and it would restart again. I finally was able to open it again after doing a force restart when the loop finished again and loaded my lock screen. However, a lot of my apps were missing, like iMessage. I could use apps like that if I got a notification and clicked on it but they were not visible from my home screen. Today, Safari was being slow and I the keyboard was really laggy while I was typing while still in the app (this is another thing that happens once in awhile; it's like the touch sensors stop responding and I'll be on the home screen trying to open apps but can't. I can swipe up and close them but cannot open them). I tried opening my McAfee security app but it kept crashing. It was weird because Instagram opened just fine (though it was slow and laggy as well). I force restarted my phone and it has entered another restart loop.

A couple other notes:

1. I do not visit shady websites, but when I looked up dating trends and clicked links to research articles on them (like pewsresearch for example, though I do not recall if it was this specific website) I was automatically taken to a naughty ad/website that I did not search for. I tried to use the back button which did not work so I closed the page it was on. This happened twice. The first time was months ago way before I had the restart loop issue, but the second time was about 2 weeks ago.
2. Months ago I also would constantly get a no SIM notification and my phone would stop picking up my T-Mobile SIM card. This was before anything I previously mentioned. This was around the time I was almost out of storage on my phone. I have also dropped my phone quite a few times but it always has a protective case on it (currently Velvet Caviar), so I doubt hardware damage is an issue.
3. I also have not done an iOS update in awhile. I think I am still on 13 or early 14. I stayed getting notifications that I was almost out of storage until I finally got notifications that it was full. I have 128 GB, about 5,500 photos and videos, and a lot of other apps and games. I checked my storage usage report where it says how many gigs my apps are taking up and nothing looked shady there.
4. I also checked my cellular data usage and it was about 1.2-1.7 GB. That seemed normal when I looked it up but I'm not sure because of everything else going on

That's everything. Do you think I have a virus or something has been corrupted? And if so, can I fix it without erasing my phone?