Thanks for the input lads! I disconnected the battery and let her sit to reset everything. Thankfully all is back to normal after that so will book her in somewhere and get her plugged in and see what's going on. It's a bit of a relief now knowing that the gearbox isn't totally knsckered as said bayerische a second hand box could be got handy enough I'm sure. A rebuild would be 1k plus I'd say. But then you would have a good box for a long time.
I'll update this after diagnosing the problem.