Erreur Additional uncaught exception thrown while handling exception.

Bonjour à tous,
J'ai fait faire un site Internet par une société et j'ai été très déçue !
Aujourd'hui le site présente un gros bug et bien sûr la maintenance s'est terminée il y a quelques semaines. Est-ce que quelqu'un pourrait m'orienter sur ce que je dois faire ?

Voilà, en permanence en bas de mon site, j'ai un message d'erreur et en plus, je ne peux plus me connecter car j'ai aussi un message d'erreur.
Merci mille fois à tous pour votre aide.

Celui du bas de page :
Additional uncaught exception thrown while handling exception.
Original

PDOException: SQLSTATE[42000]: Syntax error or access violation: 1142 INSERT command denied to user 'sesoigne95'@'10.0.89.37' for table 'accesslog': INSERT INTO {accesslog} (title, path, url, hostname, uid, sid, timer, timestamp) VALUES (:db_insert_placeholder_0, :db_insert_placeholder_1, :db_insert_placeholder_2, :db_insert_placeholder_3, :db_insert_placeholder_4, :db_insert_placeholder_5, :db_insert_placeholder_6, :db_insert_placeholder_7); Array ( [:db_insert_placeholder_0] => [:db_insert_placeholder_1] => node [:db_insert_placeholder_2] => http://www.sesoignernaturellement.fr/mentions-legales [:db_insert_placeholder_3] => 95.140.12.186 [:db_insert_placeholder_4] => 0 [:db_insert_placeholder_5] => PTwEK6r1qSjP7MHT-KSH75z13FqtBa1PMiqbmNGwYBs [:db_insert_placeholder_6] => 677 [:db_insert_placeholder_7] => 1460637725 ) in statistics_exit() (line 93 of /home/sesoigne/www/modules/statistics/statistics.module).
Additional

PDOException: SQLSTATE[42000]: Syntax error or access violation: 1142 INSERT command denied to user 'sesoigne95'@'10.0.89.37' for table 'watchdog': INSERT INTO {watchdog} (uid, type, message, variables, severity, link, location, referer, hostname, timestamp) VALUES (:db_insert_placeholder_0, :db_insert_placeholder_1, :db_insert_placeholder_2, :db_insert_placeholder_3, :db_insert_placeholder_4, :db_insert_placeholder_5, :db_insert_placeholder_6, :db_insert_placeholder_7, :db_insert_placeholder_8, :db_insert_placeholder_9); Array ( [:db_insert_placeholder_0] => 0 [:db_insert_placeholder_1] => php [:db_insert_placeholder_2] => %type: !message in %function (line %line of %file). [:db_insert_placeholder_3] => a:6:{s:5:"%type";s:12:"PDOException";s:8:"!message";s:904:"SQLSTATE[42000]: Syntax error or access violation: 1142 INSERT command denied to user 'sesoigne95'@'10.0.89.37' for table 'accesslog': INSERT INTO {accesslog} (title, path, url, hostname, uid, sid, timer, timestamp) VALUES (:db_insert_placeholder_0, :db_insert_placeholder_1, :db_insert_placeholder_2, :db_insert_placeholder_3, :db_insert_placeholder_4, :db_insert_placeholder_5, :db_insert_placeholder_6, :db_insert_placeholder_7); Array ( [:db_insert_placeholder_0] => [:db_insert_placeholder_1] => node [:db_insert_placeholder_2] => http://www.sesoignernaturellement.fr/mentions-legales [:db_insert_placeholder_3] => 95.140.12.186 [:db_insert_placeholder_4] => 0 [:db_insert_placeholder_5] => PTwEK6r1qSjP7MHT-KSH75z13FqtBa1PMiqbmNGwYBs [:db_insert_placeholder_6] => 677 [:db_insert_placeholder_7] => 1460637725 ) ";s:9:"%function";s:17:"statistics_exit()";s:5:"%file";s:55:"/home/sesoigne/www/modules/statistics/statistics.module";s:5:"%line";i:93;s:14:"severity_level";i:3;} [:db_insert_placeholder_4] => 3 [:db_insert_placeholder_5] => [:db_insert_placeholder_6] => http://www.sesoignernaturellement.fr/ [:db_insert_placeholder_7] => http://www.sesoignernaturellement.fr/mentions-legales [:db_insert_placeholder_8] => 95.140.12.186 [:db_insert_placeholder_9] => 1460637726 ) in dblog_watchdog() (line 160 of /home/sesoigne/www/modules/dblog/dblog.module

AU MOMENT DE ME CONNECTER :
Une erreur HTTP AJAX s'est produite.
Code de statut HTTP : 500
Informations de débogage ci-dessous.
Chemin : /system/ajax
StatusText: Service unavailable (with message)
ResponseText : PDOException : SQLSTATE[42000]: Syntax error or access violation: 1142 INSERT command denied to user 'sesoigne95'@'10.0.89.37' for table 'watchdog': INSERT INTO {watchdog} (uid, type, message, variables, severity, link, location, referer, hostname, timestamp) VALUES (:db_insert_placeholder_0, :db_insert_placeholder_1, :db_insert_placeholder_2, :db_insert_placeholder_3, :db_insert_placeholder_4, :db_insert_placeholder_5, :db_insert_placeholder_6, :db_insert_placeholder_7, :db_insert_placeholder_8, :db_insert_placeholder_9); Array
(
[:db_insert_placeholder_0] => 0
[:db_insert_placeholder_1] => ajax
[:db_insert_placeholder_2] => Invalid form POST data.
[:db_insert_placeholder_3] => a:0:{}
[:db_insert_placeholder_4] => 4
[:db_insert_placeholder_5] =>
[:db_insert_placeholder_6] => http://www.sesoignernaturellement.fr/system/ajax
[:db_insert_placeholder_7] => http://www.sesoignernaturellement.fr/
[:db_insert_placeholder_8] => 95.140.12.186
[:db_insert_placeholder_9] => 1460642586
)
dans dblog_watchdog() (ligne 160 dans /home/sesoigne/www/modules/dblog/dblog.module).