The nature of black holes, especially their interior known as the singularity, remains a subject of intense theoretical speculation. According to our current understanding of black holes based on general relativity, once you cross the event horizon of a black hole, it is thought to be impossible to escape or communicate with the outside universe. Therefore, any direct observations or experiences of falling into a black hole's singularity are purely speculative.
However, based on our current understanding of general relativity, it is believed that falling into a black hole would lead to a phenomenon known as "spaghettification." As you approach the singularity, the gravitational forces would become exceedingly strong, causing a significant tidal force that stretches your body into a long, thin shape resembling spaghetti. This process would be incredibly violent and result in your eventual demise.
From an outside observer's perspective, time would appear to slow down for you as you approach the event horizon due to the extreme gravitational time dilation. As you approach the singularity, time would appear to slow down more and more, eventually freezing as you reach the event horizon. However, from your own perspective, you would experience events in a relatively normal manner until the intense gravitational forces tear you apart.
It's important to note that our understanding of black holes is limited, and a complete description that incorporates both general relativity and quantum mechanics is still an active area of research. Therefore, the exact experience of falling into a black hole's singularity and the behavior of spacetime within it remain open questions in physics.