High load on MySQL and I/O Wait

Hello i'm facing high I/O wait on my cPanel server with 280 accounts. I think the cause will be Mysql, what do you think about my configuration? Raid and disk performance are ok and the server have no performance issues atm. Server Spec: 8 Core CPU E3-1275 v6 64GB DDR4 ECC /home raid 1 with 2 SSD NVME 512 GB /home2 raid 1 with 2 SSD Datacenter 960gb My sar: 11:00:02 AM CPU %user %nice %system %iowait %steal %idle 11:10:01 AM all 34.07 1.46 5.63 2.66 0.00 56.18 11:20:01 AM all 32.64 1.11 5.45 2.74 0.00 58.07 11:30:01 AM all 34.93 1.33 5.78 2.64 0.00 55.33 11:40:01 AM all 33.08 1.37 5.78 2.49 0.00 57.28 11:50:02 AM all 36.19 2.18 6.37 2.78 0.00 52.49 12:00:01 PM all 28.81 1.06 5.14 2.98 0.00 62.01 12:10:01 PM all 31.08 1.75 5.41 3.84 0.00 57.92 12:20:01 PM all 33.00 1.36 5.41 2.96 0.00 57.28 12:30:01 PM all 34.27 1.22 5.54 2.66 0.00 56.31 12:40:01 PM all 26.36 1.29 4.66 2.98 0.00 64.71 12:50:01 PM all 30.49 1.77 5.40 2.73 0.00 59.60
My my.cnf [client-server] !includedir /etc/my.cnf.d [mysqld] innodb_flush_method=O_DSYNC event_scheduler=ON log-error = /var/lib/mysql/titanium.err performance-schema=0 default-storage-engine=MyISAM datadir=/var/lib/mysql local-infile=0 innodb_file_per_table=1 innodb_buffer_pool_size=28G query_cache_type=1 max_user_connections=100 max_connections=300 interactive_timeout=300 wait_timeout=300 connect_timeout=100 thread_cache_size=128 key_buffer_size=1024M join_buffer_size=16M max_connect_errors=20 max_allowed_packet=268435456 open_files_limit=50000 sort_buffer_size=48M read_buffer_size=48M read_rnd_buffer_size=4M myisam_sort_buffer_size=128M server_id=1 slow_query_log=1 slow_query_log_file=/var/log/mysql-slow-queries.log long_query_time=2 collation_server=latin1_general_ci sql_mode = "NO_ENGINE_SUBSTITUTION" query_cache_size=5M table_open_cache=15000 table_definition_cache=-1 performance_schema=on innodb_log_file_size=15G tmp_table_size=30M max_heap_table_size=30M [mysqldump] max_allowed_packet=128M [mysql] no-auto-rehash #safe-updates [isamchk] key_buffer_size=128M sort_buffer_size=128M read_buffer_size=32M write_buffer_size=32M [myisamchk] key_buffer_size=128M sort_buffer_size=128M read_buffer_size=32M write_buffer_size=32M [mysqlhotcopy] interactive_timeout