Like many other people, you are asking for somebody to step up, read the future, and tell you what is going to happen, and when!
You are feeling anxious with the waiting. This is normal. You are just like everybody else in that - we're all human. We're used to being able to control many things in our lives, but when in the hands of a huge government bureaucracy, suddenly we can't, and we don't like it.
You've had visas previously, so you must be used to checking INZ regulations, and as far as you can tell, you meet the requirements. But INZ doesn't know you, and has to investigate and not take you on trust. Now you must give your CO time to check every single piece of your evidence, by asking a third party who is in a position to know if it's true. They won't all reply urgently. It all takes time. In the meanwhile, your CO is working 90 - 100 other cases in rotation with yours, so quite a lot of the time that is passing is time when she's looking at other people's business, not yours. At the moment, it's normal for residence applications to take up to a year to process. If you think it will be a year, you may get a pleasant surprise and hear the news sooner, but at least you won't have unrealistic expectations. Don't keep thinking about INZ. You won't hear anything from the CO unless she needs more information, or unless she has something to tell you, and that is normal.