What Causes Stabbing Pain In The Chest?

Question: Pain in right side lower chest area. Pain is low in intensity, but has periodic (every few minutes) a slight stabbing pain to add to the discomfort. Bothers me when I try to sleep. Seems to be a 24 hour thing. I have type 2 diabetes, peripheral neuropathy in my feet and have notice a little unsteadiness in my gait. Problem has slowly developed over the past couple of weeks. I have had one stent procedure several years ago on a small vein. I have noticed some general low energy during the two week period.
I do play golf and was suspicious of a muscular problem. Have tried sports creams oriented toward muscle problems, but no results have been noted.

Trying to establish what the problem is. Checking website for symptoms of cancer and heart, but haven't found anything to adequately describe the condition.

I am 77 years old and other than the neuropathy problem with my feet I am in good health and still running my consulting business and enjoying it.

Did you receive my follow up question and remarks?Here are my remarks I sent in response that may not have gone through:

I had a recent checkup with my cardiologist. Did blood work and EKG. A1C/LDL-HDL/Cholesterol/Triglycerides/PSA Test/ and urinalysis were all within my usual ranges and nothing stood out as being a problem. I also had a recent physical with my GP and everything checked out.

I do blood tests on a quarterly basis to give to my cardiologist, GP and Diabetic Dr.

Nothing like the current problem has occurred in my 77 year history. I have massaged and pressed on the affected are and there was no significant pain response. The pressing was only mildly uncomfortable and nothing like the experience of pressing on muscle soreness from some kind of athletic event.The pain appears to be internal rather than external.

The whole thing is a bit of a mystery for me.

Last AiC was at 7 down from 7.2.

Chest x-ray done in February 2017 due to pneumonia. Treated the pneumonia with antibiotics and had a follow up x-ray to confirm the clear up in march 2017.

Last Echo was done in 2016 with no problems noted.

The stent was put in after I had a minor heart problem. During an angiogram they decide to put in the stent. I don't know the name of the vessel, but I was told it was a minor one. Is it possible that the stent is giving me a problem. My symptoms for this event are totally different than for the reason I had the stent put in, but I can imagine that it would be worth checking out with my cardiologist.