I have 600% high CPU usage mysqld

I have an insane usage of cpu mysqld +600% here is the file my cnf

# Example MySQL config file for medium systems.
#
# This is for a system with little memory (32M - 64M) where MySQL plays
# an important part, or systems up to 128M where MySQL is used together with
# other programs (such as a web server)
#
# You can copy this file to
# /etc/my.cnf to set global options,
# mysql-data-dir/my.cnf to set server-specific options (in this
# installation this directory is /opt/lampp/var/mysql) or
# ~/.my.cnf to set user-specific options.
#
# In this file, you can use all long options that a program supports.
# If you want to know which options a program supports, run the program
# with the "--help" option.

# The following options will be passed to all MySQL clients
[client]
#password   = your_password
port        =3306
socket      =/opt/lampp/var/mysql/mysql.sock

# Here follows entries for some specific programs

# The MySQL server
default-character-set=utf8mb4
[mysqld]
user=mysql
port=3306
socket      =/opt/lampp/var/mysql/mysql.sock

key_buffer=64M
max_allowed_packet=10M
table_open_cache=64
sort_buffer_size=2M
net_buffer_length=8K
read_buffer_size=256K
read_rnd_buffer_size=512K
myisam_sort_buffer_size=8M
query_cache_type=1
query_cache_limit=512K
query_cache_size=0
query_cache_min_res_unit=256
innodb_thread_concurrency=0
innodb_log_file_size=128M


# Custom changes
max_connections     = 400
query_cache_limit   = 32M
query_cache_size    = 0
innodb_buffer_pool_size = 20G
innodb_buffer_pool_instances = 10
innodb_log_file_size    = 1G
innodb_log_buffer_size  = 5G
innodb_file_per_table   = 1
innodb_open_files       = 400
innodb_io_capacity      = 1000
innodb_io_capacity_max  = 40000
innodb_flush_method     = O_DIRECT
innodb_read_io_threads  = 8
innodb_write_io_threads = 4
thread_cache_size       = 100
innodb_lru_scan_depth   = 100
innodb_read_io_threads  = 64
innodb_write_io_threads = 64
open_files_limit        = 4096
table_open_cache        = 2048
join_buffer_size        = 128K
read_buffer_size        = 128K
log_warnings            = 2
key_cache_age_threshold = 64800
innodb_change_buffer_max_size = 10
max_write_lock_count    = 16





# End custom changes

# Where do all the plugins live
plugin_dir=/opt/lampp/lib/mysql/plugin/

# Don't listen on a TCP/IP port at all. This can be a security enhancement,
# if all processes that need to connect to mysqld run on the same host.
# All interaction with mysqld must be made via Unix sockets or named pipes.
# Note that using this option without enabling named pipes on Windows
# (via the "enable-named-pipe" option) will render mysqld useless!
# 
#skip-networking

# Replication Master Server (default)
# binary logging is required for replication
# log-bin deactivated by default since XAMPP 1.4.11
#log-bin=mysql-bin

# required unique id between 1 and 2^32 - 1
# defaults to 1 if master-host is not set
# but will not function as a master if omitted
server-id   =1

# Replication Slave (comment out master section to use this)
#
# To configure this host as a replication slave, you can choose between
# two methods :
#
# 1) Use the CHANGE MASTER TO command (fully described in our manual) -
#    the syntax is:
#
#    CHANGE MASTER TO MASTER_HOST=<host>, MASTER_PORT=<port>,
#    MASTER_USER=<user>, MASTER_PASSWORD=<password> ;
#
#    where you replace <host>, <user>, <password> by quoted strings and
#    <port> by the master's port number (3306 by default).
#
#    Example:
#
#    CHANGE MASTER TO MASTER_HOST='125.564.12.1', MASTER_PORT=3306,
#    MASTER_USER='joe', MASTER_PASSWORD='secret';
#
# OR
#
# 2) Set the variables below. However, in case you choose this method, then
#    start replication for the first time (even unsuccessfully, for example
#    if you mistyped the password in master-password and the slave fails to
#    connect), the slave will create a master.info file, and any later
#    change in this file to the variables' values below will be ignored and
#    overridden by the content of the master.info file, unless you shutdown
#    the slave server, delete master.info and restart the slaver server.
#    For that reason, you may want to leave the lines below untouched
#    (commented) and instead use CHANGE MASTER TO (see above)
#
# required unique id between 2 and 2^32 - 1
# (and different from the master)
# defaults to 2 if master-host is set
# but will not function as a slave if omitted
#server-id       = 2
#
# The replication master for this slave - required
#master-host     =   <hostname>
#
# The username the slave will use for authentication when connecting
# to the master - required
#master-user     =   <username>
#
# The password the slave will authenticate with when connecting to
# the master - required
#master-password =   <password>
#
# The port the master is listening on.
# optional - defaults to 3306
#master-port     =  <port>
#
# binary logging - not required for slaves, but recommended
#log-bin=mysql-bin


# Point the following paths to different dedicated disks
#tmpdir     = /tmp/     
#log-update     = /path-to-dedicated-directory/hostname

# Uncomment the following if you are using BDB tables
#bdb_cache_size = 4M
#bdb_max_lock = 10000

# Comment the following if you are using InnoDB tables
#skip-innodb
innodb_data_home_dir=/opt/lampp/var/mysql/
innodb_data_file_path=ibdata1:10M:autoextend
innodb_log_group_home_dir=/opt/lampp/var/mysql/
# You can set .._buffer_pool_size up to 50 - 80 %
# of RAM but beware of setting memory usage too high
#innodb_buffer_pool_size=512M
# Deprecated in 5.6
#innodb_additional_mem_pool_size = 2M
# Set .._log_file_size to 25 % of buffer pool size
#innodb_log_file_size=5M
#innodb_log_buffer_size=8M
innodb_flush_log_at_trx_commit=1
innodb_lock_wait_timeout=50

character-set-server=utf8mb4
collation-server=utf8mb4_general_ci

[mysqldump]
max_allowed_packet=10M

[mysql]
# Remove the next comment character if you are not familiar with SQL
#safe-updates

[isamchk]
key_buffer=20M
sort_buffer_size=20M
read_buffer=2M
write_buffer=2M

[myisamchk]
key_buffer=20M
sort_buffer_size=20M
read_buffer=2M
write_buffer=2M

[mysqlhotcopy]


!include /opt/lampp/mysql/my.cnf 

                                                                                             

I don’t know if this is the right code to use for better performance, I’m using wordpress.
I’m experiencing some problems with my mysql server When I run top command, it sais that mysql process has taken over 350-600% of CPU I’m running ubuntu 18.04 with 32 GB RAM