Don't stress-although I know it's stressful.
Last month I had a package stuck in customs for two weeks. It turns out, the shipper failed to provide all the necessary information on the forms required for customs clearance. Once the package stopped moving, it really stopped. I called and emailed the shipper and I probably called UPS about a thousand times. Every time I spoke to someone I got a different story. I was frustrated. A full week after the information was provided, it finally got back on track.
All international shipments need to clear customs. Period. This is part of the process. It is possible, like my shipment, customs may need additional information. The point is, however, you don't know. Tomorrow, call DHL and ask to speak to their customs department. A regular representative will not be able to help you. Once you get the right department, find out 1) why your shipment stopped; 2) is any information missing and if so; 3) what do they need to get this parcel moving forward 4) where should the information (if required) be sent (get an email); 5) whether they can accept it from you or the shipper and 6) a case ID number, if there is one.
Finally, get the name of the person you speak to and get a phone number and/or email to find out how you can directly reach that department again should you need to.
Unless this has been labeled an explosive (I joke not, this happened to me years ago with work-related documents I sent via FedEx), it should move forward.
Please keep us updated, and finally, sleep well---it will all work out.