He's been quite cautious since aged 3. Won't go in tunnel slides, down bigger slides at soft play (not huge - just 'normal' big). He's recently started with stairs when out - if there are any gaps in the back of them he really freaks out, last week he ran out of the train station because it was a wider than usual staircase, even though there were banisters and the steps weren't steep. He wants to walk on low walls but then freaks out when on them, ditto lots of other things and it breaks my heart a little bit.
He's improved since we started him at gymnastics (a preschool one but it's perfect for his level) and he's become more ambitious with jumping off the last couple of stairs at home for example. However, other things seem worse - like jumping in the swimming pool at his lessons he won't even entertain. He's scared of his head going under but if I try to offer solutions to stop that happening it doesn't help.
Has anyone else had this? He's not anxious in lots of other areas, though he'll never be Mr Outgoing (and that's fine!). Generally, he's happy and settled at school and will speak up there and engage well with others, has friends etc. I just really want to help him with these irrational but clearly very overwhelming fears.
Any tips for distraction / encouragement / methods to try to work through things with him?
Thank you 