SR22 pilot reported malfunction with autoflight systems during descent and approach resulting in temporary loss of control. Pilot disconnected autopilot and continued to landing.

Narrative

I was descending for a visual for Runway XXL. As I descended lower from an initial cruising altitude of 8000 ft I began experiencing occasional moderate turbulence. During the initial descent I received a single stall warning which I attributed to the sharp turbulence I had just experienced. As I descended lower the aircraft experienced increased moderate turbulence. The Controller had also advised a prior aircraft of wind shear on final approach. As i continued the descent and intercepted the final approach course the stall warning system started triggering repeatedly with both visual and aural alerts. I also noticed the PFD (Primary Flight Display) indications seemed incorrect with the bottom of the speed tape red in color. I had slowed to below my flap speed and decided to add in 50 percent flaps which seemed to quiet the stall alerts momentarily. As I continued the approach the alerts returned almost continuously along with the strange PFD indications. I disconnected the autopilot and found very heavy control forces. I decided to level off to assess the situation and received an 'Autopilot Engaged' aural alert from the Perspective system indicating the envelope protection system had activated. I felt the servo activation in the control yoke and a pitch down movement. At this point I held down the autopilot disconnect switch to override the system. I immediately [advised ATC] because I realized I could not safely land the plane and was not sure I had full control with the envelope protection system engagement. After [advising ATC] I reverted to my training prioritizing aviate; navigate and communicate. I asked my passenger who was sitting in the copilot seat to look down at the breaker panel next to my right leg and pull the autopilot circuit breaker. She could not initially find it but began reading off the various breakers. When she said 'stall warning' I asked her to pull it which immediately silenced the continuous alerts. At the point I felt I had full control of the aircraft and informed the Tower that I had cleared the [priority]. They issued turn and climb instructions and a handoff to Approach which I complied with. I was vectored onto the final for [Runway] XXL and executed a safe landing requiring full rudder deflection and heavy aileron use to hold the centerline in the strong crosswind. I also experienced strong wind shear over the numbers. This cemented in my mind the decision to [advise ATC]. Some of my takeaways are: 1. Having a deep understanding of how the technically advanced systems work is very important in situations like this 2. Reverting to aviate; navigate and communicate priority order is imperative when being overwhelmed in the cockpit. 3. Don't not hesitate to [advise ATC]. It allows you to do what is needed to keep the flight safe. 4. After [advising ATC] ATC kept asking questions which was incredibly distracting. Don't be afraid to use the word 'standby' or completely ignore them as you work the problem.