Jon, thats really tough, I kinda know how you feel.
7 years ago my wife, kids and I moved from a rented 400yr old cottage in the tiny village that I was born in. We moved to a larger village on the outskirts of town. Previously I had gained enough permission to walk (and hunt and fish) just about anywhere, now I had to start from scratch.
Gradually, by working the footpaths, I got to know landowners - and now even though I don't hunt the land I can enjoy lengthy strolls off the beaten track watching badgers, deer foxes etc.
Last night I was out til 10:00 pm, lovely harvest moon and loads of wildlife all around me.
Genuine country men will always manage to get access to the places they love. Keep your chin up mate, I really hope it works out.