Why am I so focused on my changes in my bodily sensations all the time?

You might be hypersensitive. Small discomforts and sensation are common everyday for everyone, but if you tend to dwell over them, especially if you have anxiety issues, you might experience them as more prominent than they actually are.

People experience life differently. Often The same person going through the same thing at a different time would experience it differently, and we notice changes of any kind. If you are very aware of you're physical sensation; that's just part of how you see life. I wouldn't say there is anything wrong with that, unless it's interfering with other parts of your life.

Your body knows when something is wrong. Sometimes, we are aware of it and any small changes can be overwhelming. If you are feeling any type of stress, depression or even are just sad for a while, your body starts to fight it.

Changes in your bodily sensations cause you to be focused because they're changing all the time. It's completely normal to be focused on that. I'm not sure who wouldn't be focused on that.

Maybe you are a sensitive person and you feel most bodily sensations then others. Sometimes that is a good thing you know yourself better in a more intimate way.