Hey there, I had this same problem (twice) in my business. The first time my accountant told me to change to a limited company, which 'resets the clock' so I could start again from 0. A later accountant told me that wasn't quite right, so I'm not sure if it's right for you, but check. My idea was to redo my budgets taking into account vat FROM THE START this time, so when I hit the threshold the second time I was able to register on the flat rate and pay VAT. My company was already the most expensive in the area, and it unfortunately co-incided with the big increase in national minimum wage to the 'living' wage (although of course it's not a living wage at all). My staff I already paid higher than that, but to keep the difference between the salary of a new started, and someone with many years experience I had to increase all wages just the same. And of course pensions reared its ugly head at about the same time.
We looked at separating the business into pet care as one business, and training of owners with dogs, and the training I give to other pet care professionals, as well as ebooks I write as a separate one, but that side of the business was much smaller and didn't make much difference. We looked at moving other services over, ones that only I covered (not my staff), but both companies having the same director, using the same vehicles and equipment etc, I felt that wasn't a risk I wanted to take.
I did have a drop in profits, although was still profitable, but when a few of my staff left after a couple of years, I had to make a decision. Push past by growing much bigger to get my full profits back, or downsize to drop under the threshold.
As I had some turmoil with my health, I decided to downsize and now work alone again. I'm looking at new directions for my business, which might not even get to the vat threshold again, but this time I will be ready not just to meet it, but go flying past.
Or I'll semi-retire.
Hope that has given you some ideas, but was quite therapeutic to type out.
