The IRS does tend to take a long time to process things don't they. Many people are still waiting for their returns. The IRS will send your return to you as soon as they are done processing it. It could be connected to the reason you amended your return. They may be holding it until they have all the right information. However that's actually unlikely. Chances are your file is just sitting in a line somewhere waiting to be reviewed
With a little patience I'm sure it will get to you soon.
Don't forget that Turbo Tax has a handy Track My Return tool
You can also request information about your return from the IRS as well
https://www.irs.gov/