I can develop a C++ program to do exactly that for you; automatically post content, send dms, as well as any other automation for the TG automation such as login checking and automatic signing in etc.
I would also build a fast rendering GUI to go with it which would give you configurable options, status updates, and a log file to show you what has been completed.
I hope we can discuss this further, as I would very much like to develop this software for you and present my ideas for it.
I would start working on it as soon as possible, and provide support for some time even after the order has been completed.