My test is next week and I'm not confident of passing

Had a mock test and scored 4 major faults and 14 or 15 minor ones, actually several of the latter became a 5th major fail as they were all the same thing - not looking over my right shoulder before moving off! The instructor asked, did I have a sore neck, and I do - months of working from home behind a screen. That one is easily remedied - now I just twist my body so that I'm looking out the rear side window. (the instructor said at the start that in his experience, the average score for a first mock test was 4 majors and 14 minors so I didn't do too badly - he seemed somewhat surprised!)
But I still sometimes stall when doing a hill start (loads of inclines in my part of North London) and am still struggling with meeting traffic - the one where a road is made narrow by parked cars on either side so that there's only room for one car. I think my difficulty is having to look on the right as well as the left and check for gaps in the parked cars, then anticipate if the
oncoming driver can / will pull in on their side, or whether I should.
Part of the problem is I'm not looking far enough ahead; I think some learners have a sort of 'tunnel vision' whereby they don't see what's on their periphery or far away (I remember hearing about this in a martial arts class, doing self-defence; the idea that the stress of the situation causes tunnel vision).
I am beginning to train myself to look 100-150 yards in the distance and then look nearer, it also helps with e.g. lights and zebra crossings if I've already spotted them a long way away. But f*** me, I certainly am a slow learner, definitely not a 'natural driver'
I was thinking of postponing the test, but they're like gold dust at the moment and probably the next earliest date would be November or December. So I figured I may as well take the test for the experience; hopefully not failing before exiting the test centre car park like someone else I recently heard about!
That's the problem with tests at the moment; due to Covid, if you make a serious error the examiner tells you to return to the centre and it's over. A bit of a pisser, as in theory it could be over in 5 minutes and that's £62 down the plughole. But I understand why they're doing this - trying to minimise their contact time with several people each day.