I set up a domain for my server and my friends can't join now.

What happened was my friends wanted to play with me on my server. I go to the website dot.tk and make a domain from my ip. They then JOIN the domain and it works. I'm building on the world and a creeper blows up. So, I stop the server, delete the world file, and readd the unexploded house one. (backup world file) My friends now can't join so I try and give them my external ip and it gives them the same message: io.netty.channel.AbstractChannel$AnnotatedConnectException: Connection timed out: no further information
I've port forwarded and disabled the firewall and all that. I can still connect using my local ipv4 (computer ip) address. I've checked for antiviruses and all of that. Please help.
(This is a Bukkit 1.14 Server)