2020 Toyota Camry forward collision avoidance problems

While driving the Camry at 45 mph among the flow of traffic on a state highway in Florida, out of the blue the vehicle's speedometer on the instrument cluster was replaced with a flashing red box and the brakes applied themselves fully with no command or input given whatsoever. The Camry immediately screeched to a stop in the middle of the road within a couple seconds, causing the vehicle behind me to slam into the Camry at full speed.

I bought a new toyota camry 2020 se on october 2020 from toyota downtown los angeles less than 3 months later. I've only driven it 800miles. Today as I was driving to work I noticed that I had to press on the break harder than usual. Also it lags when starting up.