Not being able to connect could be multiple issues:
1. Your eqhost.txt file is incorrect, or was accidentally saved as eqhost.txt.txt, which can happen depending on how you edit the file.
2. If you live in a dorm or are playing at work, you might be using a proxy that is blocking port 5998, which means you won't be able to connect.
3. If you are running a P2P or Torrent program, it might be using all of your bandwidth. Try turning them all off.
4. You may have a firewall that is blocking EQ. Disable all firewalls.
5. If you are running a Dual Core CPU or Windows Vista, you will probably need to read the following post and apply at least one of the fixes listed in it:
http://www.eqemulator.net/forums/showthread.php?t=25327
6. You may need to adjust your Windows Desktop and/or your Everquest Resolution settings.
7. If you are using an illegal copy of Everquest Titanium, or the wrong version of EQ, it won't work. You need to get the retail CDs from the store or buy them online.
And there are other reasons as well. Giving more information on your problem is always helpful if you have more info to give.