It's NORMAL for your penis and testicles to shrink when you go into the water. Lots of guys call it "shrinkage."
Don't worry about armpit or facial hair yet, it often comes later in puberty, 15 or even 16 on many guys.
You're NORMAL. You're size is average for 14 year old too. Don't compare yourself to others, everyone develops differently.
Hope it helps.