Thanks for the support guys, I really needed it - a real tough couple of days.
Anyway an update.
Spent yesterday just taking him out to the road, keeping him on a very short lead and on the inside (my weakest side) as best I could, If we saw an oncoming car I turned, if one came up behind I stayed on track till it just passed us then I turned.
Some success, maybe he stayed with all four paws on the ground about 2 out of 10 attempts so not a complete failure.
Today in the lane this morning I was lucky in that the district nuse was visiting just as I reached where she was going to be stopping. I managed to keep him at my side. all four paws on the ground while she pulled up and parked. We also managed to pass two delivery lorries without too much stress and another parked lorry he managed to stay calm whilst I chatted to the driver.
Popped out to buy a harness this afternoon. What a difference already
Still tried to lunge at the cars but couldnt gain enough leaverage so had to make do with barking
A nice sedate walk to the field, then coming back down the lane, once again done the about turns when cars came and he was pretty good, gave up a lot quicker then usual. Then to top the lot managed to sit at the top of the lane for 20 mins whilst I chatted with a neighbour:) He did start by getting primed for the cars but soon gave up and just sat there as good as gold and a very sedate walk back to the house with barely a backward glance at the cars
So although I know the harness isnt the be all and end all, at least I know I can control him a lot better so am in myself a lot calmer. Lots of work to go as I do want him back onlead walking nicely again. Ive gone totally against my own advice and brought a load of highly processed treats (extremely high value in his eyes) to use to keep him focussed on me and am clickering like its gone out of fashion, if he even looks at me he gets a click and a treat - poor horse in the field next door is getting mightly confused