Okay - any advice would be great.

Over the past few months, I've been suffering a variety of symptoms that feel like they might be heart-related.

I'm 29 years old, a bit overweight...my main problems are that I have this constant sensation that my heart is beating hard. It doesn't beat fast (my resting pulse hovers around 60 most of the time) but just hard. I can feel it thudding in my chest, and when I lay my hand on it I can really feel it pulsate in my palm. My carotid arteries are also constantly pounding away, right down to my collarbone - even pulsating in the little notch between my collarbones. My stomach bounces along with my heartbeat, and I can see my clothes shake when the pounding is at its worst. Sometimes it feels like my body is rocking with my heartbeat.

However, I have seen 8 different doctors over the course of the past few months. I have had 3 EKGs, a chest X-Ray and countless physical examinations. I've been tested for thyroid and had other blood tests to check my heart. Every doctor has suggested anxiety is behind all of this. No murmurs have been heard, no pulsating masses found, nothing untoward has been found at all. My blood pressure is around 117 over 76. No doctor feels that it has to be investigated any further.

Could anxiety really be causing all of this? The physical sensations are certainly real. Others can see my neck pounding hard. Others can feel my heart thudding in my chest. But am I doing this to myself? I am ready now to challenge my anxiety if this is indeed what it is.

Thankyou in advance.

With a normal blood presure and a normal steady heartrate, any perception of beating hard is just that, a perception. It's oven just the result of hypervigilance, looking too hard.
I doubt there is anything wrong.