Fast/Rapid heartbeat

So it seems like everytime i get in the shower, My heart starts to beat really rapidly. But
i can't feel it unless I put my hand on my chest or feel my pulse and when I do I feel like my heart's going crazy. If I sit down in the shower for a while it starts to beat normally again. When this happens, I tend to feel a little fluttering sensation in my chest and I feel a little uneasy which causes me to check my heart rate.
I also suffer from Panic attacks and general anxiety, so could this just be happening because of my anxiety or is it the hot water?

Another thing that also happened to me was i was hiking with my friends on a very steep hill, and my heart started beating faster like it usually would during hiking uphill, But the thing was after we had stopped hiking and were just sitting/walking on flat ground, my heart was just racing and racing so fast, even after we had stopped the hiking. Anyways, it felt way too fast to be normal and everyone i've asked about this told me that it's my anxiety acting up, but I'm not really sure. Also When it was happening I was feeling anxious, but I don't know if that was because i got nervous of my heart beating faster or because I was having some sort of anxiety attack.

The main point is, it felt way too fast, I was scared to death, and I would like someone's opinion.

Also I just turned 18, female, no history of heart problems, had a normal EKG, and normal blood pressure.
also struggling with anxiety/panic issues.

[CCFheartMD10]

This is a difficult problem - it is a feature of anxiety that it makes your heart beat faster, and it is possible that this is all it is. Of course it is also possible to have a fast heart beat (arrhythmia) due to a number of other conditions. It can be difficult to tease these out. A shower is certainly a very unusual trigger for an arrhythmia, which leads me to think your anxiety is likely to be responsible. But it would be reasonable to have a Holter monitor and see a cardiologist or cardiac electrophysiologist to help to clarify this.

[Nessajo89]

I have alot of anxiety problems too but when ur in the shower dont think about your pulse or what your body is doing. Just take deep breaths. Your heart rate probably increases because you make urself worried and anxious causing you to freak out which increases your heart rate. Going up a hill, you prlly just had a bout of adrenalin rush. Are you on any anti anxiety pills? I'm on ativan twice daily. It helps a ton! Dont spend your days putting your hand up to your pulse and thinking about it cuz you freaking out can make ur heartrate increase.