Because your code is so long and there has been cut-and-paste issues, as a check

Variables[Integrand]

results in

Are these the variables that you expect?

If you are potentially waiting three days for this to complete then you may not want to interrupt that to verify and correct these

If you scrape-n-paste your expression from your screen into a notebook then, with a bit of hunting, it shows that

You have Cos[θ] ] that should probably be Cos[θ] OR maybe that hints that when you were scrape-n-pasting your expression to make you post that some part of your expression was lost. That would be much worse.

You have [Mu]y that should probably be \[Mu]y OR again perhaps some part of your expression was lost.

Carefully checking and fixing those should help anyone who wants to scrape-n-paste this off their screen into their notebook to try to help you.