Not sure which gamertag you are Dee, but don't sweat it. Many were guilty of it, and if the roles were reversed, I would be the same. It isn't so bad if there is only one to do, but I've done over 60 invites so far. Some were done in batches of 5 or 6, others 1 at a time. And I struggled to remember the order they came in, so a bulk text to all was tricky.
Great to hear from those getting in, and I am happy to try again for those that don't make it this time, but give it until the weekend, MS send them out in a curious order.