So in December I'd got to week 7 and was actually enjoying it then had to stop due to hip pain. Blood tests, X-ray and bone scan all fine. Anti inflammatories helped a bit and at least I could start walking without pain. Been seeing a physio and a chiropractor which both helped a lot - done a couple of hikes pain free which wouldn't have happened a month ago.
Been given some strengthening exercises to do but not really had a specific diagnosis as to what the problem is!
Going to attempt to restart couch to 5k tomorrow and really hope the problem doesn't immediately flare up again. I've booked to do a 5k and 10k race in September and don't want to have to cancel.