Truly something to get over as it takes away driving pleasure, and I personally love to drive, find it relaxing, always have, and more so in a performance car with all around capability.
But do understand the feeling as have been there, but after one particular car took a few knocks (new bumper, new rear door, repaired wing) despite my caution, and the after was always fine, decided to just completely move on from worrying and attitude now is that if anything happens you simply get it fixed.
Someone just posted on here that their 2014 plate has clocked 108,000 miles and is running as well as ever, these cars will do way beyond 100,000 if maintained, and so again do not worry on such things, just run car to point want a change and then you sale it for what can sale it for, and move on to your new car.
This will make the detailers cringe, but my TCR not been washed since autumn, pointless! its filthy again within a day, so it always has a winter coat of muck on till Spring (It does have a Collonite coating though underneath that) and it might not look gleaming out there, but the rugged winter look actually kind of suits it.
Honestly, the day you move on from worry and just drive the car for the enjoyment is freeing, so try it