I cant connect to my own server

So I looked through the forums but none of it solved my problem and yes before you ask I did look through the logs and I know your gonna say well you can just delete the playerdata but could you atleast tell us where it is before you say that I mean you act like all of us know this stuff, I mean obviously if we did we wouldnt be here in the first place.

Here is what me logging in then getting kicked out looks like on the log:
57[01:23:16] [Server thread/INFO]: X5oINFERNOo5X joined the game
58[01:24:00] [Server thread/INFO]: X5oINFERNOo5X lost connection: Disconnected
59[01:24:00] [Server thread/INFO]: X5oINFERNOo5X left the game

Im sorry I was so rude ^^^ its just this is really aggravating me.
thx for the help if you do

Quote from Roman

Delete this file and upload your world again. Please make a backup before deleting or changing anything in your world folder in case that your problem is not related to your player data.

so i didnt know how to back it up and it wasnt a problem with the playerdata because that didnt fix the problem so idk if what i just did was really bad but i dont think it was. anyways what im saying is deleting it did nothing i still have the same problem so what do i do now

X5oINFERNOo5X1
Vanilla 1.12.2 and thats it

client as in the version im using for minecraft cuz if so im only using optifine which i had before and it worked fine then the next day when i tried to get on it disconnected and now its done that since and no i havent tried reinstalling
but if you mean like the minecraft launcher as in client then same thing
sorry honestly dont know much about this stuff

oh and i have this same problem on any other aternos server i try to join which shows its not just mine and also the fact that other people can join mine with no problem shows that

are you sure this will work because i dont want to do this for nothing and then have evverything i downloaded gone
nvm i just did it anyways and if it works thx for the help if not ill still have to bother you sorry

it worked for a little then it started doing it again
idk cuz it could be that im using optfine although when i tried reinstalling again and going on without optifine it still disconnected me
plz help

no I have great internet connection its honestly the client i believe but idk why what you said didnt fix it permanently

ok so it just started working again and i think that i was right that it was optifine but if it does it again later then we know it wasnt and ill let you know and thx for all the help

aaaaaand it did it again
so i was playing for a little while then out of nowhere it says it was forcebly closed and then i tried getting in again and same messagge
UUUUUGHHH

please help

ok well thx for all your help and i guess ill have to deal with it