Congestion control in 5G New Radio (NR) Vehicle- to-Everything (V2X) sidelink communications is a challenging task, mainly due to the distributed nature of the Semi-Persistent Scheduling (SPS) algorithm used in Mode 2 operation. In this paper, we define an adaptive algorithm to set SPS parameters so as to minimize the average Age of Information (AoI) of cooperative awareness messages. The algorithm is based on insights gained from an analytical model of SPS, and its performance is evaluated through simulations. We present initial simulation results demonstrating the convergence and precision of the proposed algorithm, which allows for the rapid attainment of optimal values of Channel Busy Ratio (CBR) and AoI.