Players in my server gets constantly disconected

hi. for some reason all the players in my server disconnects randomly. first i thought it was lag, but it kept occurring like so many times. this is the first time it has happened to me in 3 years since i had this server. so apparently something went wrong.
i have like 52 plugins (always had)
7gb server
how do i fix this.

something like this happens
jithins lost connection: user was kicked.



this is only happens to ONLY me, but for everyone else its other reason(like generic) even still i don't get generic reason for disconnecting. all players quit at same time. but the server is still up Plugins :BukkitCompat, PlayerLogger, Vault, Multiverse-Core, TreeAssist, RemoteToolkitPlugin, MachinaCore, MachinaFactory, AntiAdvertising, PluginUpdater, TARDISChunkGenerator, HoverPad, MachinaPump, MachinaBuilder, Profiler, Votifier, ColorPortals, mcMMO, Lift, TimTheEnchanter, Jobs, Citizens, WorldEdit, Towny, uHome, SimpleAutoAnnouncer, JSONAPI, HealthBar, PermissionsEx, Builder, TerrainControl, Questioner, WorldGuard, Commandspy, ToolStats, HandCommandID, Minigames, CoreProtect, CraftBukkitUpToDate, Lockette, Modifyworld, MobHealth, Essentials, MachinaDrill, TARDIS, MachinaRedstoneBridge, MachinaPlanter, OnTime, Sentry, ChatManager, EssentialsProtect, EssentialsSpawn

server ip is 98.109.57.36