You can definitely get better at the tests by practicing, especially if they make you uncomfortable.
I've done a couple, quite enjoy doing them. Got similar scores on both.
One of the biggest criticisms of them is that you can get better with practice, I think that's reasonable, you can get more intelligent with practice.
I like playing chess to keep my mind ticking over, but I really struggled (failed) achieving mate with just rook & bishop remaining.
Alison, stop worrying there're people with real problems. Based on your writing & language I'd have a guess at a score of 115 ish.