Just don't let it worry you too much is the main thing.
Excellent advise in this thread, as usual, and especially SpinWings, where he talks about the touchdown spot in front of the glideslope.
There may be something else; If you have ever had a lazy eye, or don't even know about it, (mild astigatism or some other reason) then it could quite well be that when you are getting stressed that you are not getting the best benifits of the two eyed distance measurement, or depth perception.
See if you can short circuit the problem by giving yourself markers to work with. spinwings' is ideal.
Me I had that problem, i could never land a fixed wing on the same spot twice, when learning circuits under indentical conditions each time. That's when I learnt to look down, mark, power back a bit (the same bit each time), look down , mark, etc. just a bit of extra work and at the end of the day (oh dear that expression again) you will end up being smarter than those who don't have to work at it.
Those who have to work hard to get there have well proven their good capability compared to those who find it easy, i have found.
Certainly when / if the real crunch comes all of that practice will mean that you will without thinking point the machine, and control it easily, at the best and only spot around, that you have already picked out and it will be simple.
Above all if you feel that you are getting a bit crowded with the instruction ask your instructor if you can do something else for a while, or practice the sequence for a bit with someone else. no harm done for sure. go have a drink of tea or milo, not coffee.
all the best tet.