I have had a tender sternum for over a year now which basically happened because of chronic slouching,
getting up after slouching for a long time, and feeling something "stuck" in my sternum when i went to lean back, which results in a cracking/poping sound and of pressure/pain. After doing that repeatedly i slowly lost mobility in that movement of leaning back with your head/neck going down towards the floor and stretching out your upper chest area. Because of this loss of mobility I stopped being able to crack my sternum sometimes after slouching, and because of this it started remaining in constant pain/tenderness , feeling like it needs to be cracked but because of the loss of mobility i no longer can.

Now on top of this sternum area being tender and sore 24/7 , i have started developing some other strange symptoms that feel like heart problems. I have had ecg, stress test, echocardiogram and even an MRI bloodwork and pretty much every heart test besides an angiograph (sp?) and my cardiologist told me theres nothing wrong with my heart but that it was slightly larger then normal but that I had nothing to worry about and didn't suggest I do anything other then eat healthy and excersize regularely.

The biggest concern for me is not the pain anymore thats always present in my sternum , but a host of other weird pressures and pains all over my chest. specifically theres 1 pressure spot both above and towards my side of my right nipple, same on the left. it is hard to tell if its on or under the rib, but it feels like its right under it. this pressure sometimes pulses with my heartbeat, sometimes is a constant pressure, and sometimes has this weird shaking feeling. i also get similar strange pulses on and around my sternum. They seem to be worse when im sitting or lying down on my stomach (the only comfortable way i can sleep) when i lie on my back they subside usually. but sometimes are still there anyway.

They cause a great deal of anxiety for me to the point i can't even sit and watch a movie anymore because theres constant weird feelings all over the top of my chest that cause me to worry and not stop thinking about them.

These odd sensations all started around the same time I started having chronic pain and tenderness on my sternum due to not being able to crack it anymore. the pain has been there for over a year, sometimes i move my upper body a certain way I can feel the pain where the tenderness peirce like a knife kind of.

So basically im wondering if all these incredibly uncomfortable chest sensations could be caused by the chronicly painful and tender sternum area, and if continueing to put pressure on it like when im sitting or lying on my chest would agrivate and cause those symptoms more.

And further, if not not, what could cause the kind of symptoms Ive mentioned? specifically different areas all over my chest vibrating/pulsing/pressuring/ all these odd sensations. Thanks