Ok, so I know I don't have the greatest ISP, Time Warner Cable, but I've been able to play FFXIV since August2013, with the occasional disconnect once in awhile. However the last month, maybe 2 months already, Its been really bad. Yesterday I was logged in for about an hour before I was disconnected. Sometimes it's so bad that I get disconnected every 5 minutes or when I get disconnected and try to go back in, in a matter of seconds, get kicked out again. The reason I ask if it is really my ISP is because when I do Coil, I'm on Skype with my FC. I would get disconnected from FFXIV but still be on Skype talking to them. Also, I have tried resetting my internet, problem still occurs. I've called them up and they would reset my internet from where they were. I've also had two modems already replaced by my ISP. So is it my ISP or is this a problem with FFXIV itself?
I'm sorry if these sound like silly questions but i'm a nub when it comes to these things.

Also, what is the difference between the 90000 Error and the 90002 Error? I get both.