Not always I'm afraid. I nearly drowned in a pool when I was a child and ever since then cold water covering on my face makes me nearly hyperventilate. I have the wherewithal not to breath in the water, but my need for oxygen still goes through the roof. I tried for years in cold showers and swimming pools to overcome it and at 37 still can't swim and not much progress on the lasting more than a minute or two holding my breath when under a cold water shower head.
Well a phobia of drowning, or water, is a rather powerful one, especially if it's brought on by a real near-death experience.
A flower, however, you can get used to once you realise it's not so bad. I also did say "sometimes," humans are very different and what works for some won't work for others, this is true of most things.
For example I have a phobia of balloons because my dad and brother would pop them behind me as a kid and scare me, it's not as extreme as a phobia of water or drowning but it's something that still haunts me.
Nowadays I'm not as paranoid as I used to be but being around anything under pressure, or seemingly under pressure will make me uneasy, to the point where fake boobs scare me if they're bad enough and I've never gotten over that.
I've gotten over smaller things, like visual phobias including Tryphoboia and needles with exposure therapy though, mind you the latter is because I'm under a lot of medical treatments and stuff but eh~
Apologies if I seemed dismissive of your plight though, that's a terrible situation to be in and I hope that it gets better someday even if it's a little bit.