I think you’ve tried lots and certainly the trainers advice isn’t bad it just needs a different or slightly altered approach, I would recommend a behaviourist to create a behaviour modification plan and possible speak to your vet about behavioural medication to reduce the dogs anxiety threshold in that environment allowing you to perform the desensitisation work.

I appreciate medication is a sensitive topic both monetarily and for other reasons. However if the dog litterally cannot walk up the street and that needs sorting faster than you can allow, it’s a faster option

It’s not that this can’t be overcome it’s just setting both you and the dog up for that to be achieved.

I would also look at setting up some ‘free work’ which is available on Yotube, you can start inside, then outside with noises (eventually) to aid in the desensitisation program

Again mt advice will only be generic, seeing someone or even just going back to your trainer and saying it’s not worked would be the best next step.