I tested your graph and it ran without any problem on my machine. See the image below and read the following hints that might help for running the energy simulation using GBS nodes in loop.
1- What I would suggest is to create the GBS project outside of the loop so the graph does not go over creating the GBS project node over and over (Saves time). It is better to create the project outside the loop and then pass the project ID into the loop. You can test if the project is created appropriately by disconnecting it from loop for the first time and then pass the ID to the loop as well.
2- The Dynamo energy analysis nodes may time out if the run stays on the queue on GBS website for a long time. A few of the nodes can get the timeout as input, but some of them have it hard coded (you can have a look on the source code of the package here if you are interested).
3- Since you are interacting and updating Revit in each iteration and then exporting the gbXML file, it is essential that you make sure that the transactions are made in Revit before exporting the xml file and start uploading it to GBS website. You can create sequential steps in Dynamo using Function.Compose node. Here is a link to a video from Glenn Katz at Stanford class is using the same process for optimization using Optimo package. He uses function.compose node to manage the process.