ok so this is an example of how records should look in you zone (soa).
web-worlds.com. A 18.104.22.168 0
mail A 22.214.171.124 0
ns1 A 126.96.36.199 0
ns2 A 188.8.131.52 0
www A 184.108.40.206 0
web-worlds.com. MX mail.web-worlds.com. 10
web-worlds.com. NS ns1.web-worlds.com. 0
web-worlds.com. NS ns2.web-worlds.com. 0
Ok. so here we have the fullstops at the end of your domain and your name server, just copy that in you Zone records in ispconfig3.
Remember that it can take up to 3 days for things to work properly, and also because your domain name is the same as your Name server (ns1.web-worlds.com etc) you might have to create a Glue record with your registrar.