What Causes Strong Thumping In Abdomen Between The Breast Bone And Naval?

I av been having very strong thumping in my abdomen between
my breast bone and naval slightly to the right. it started 4 months

ago with flutters but now very strong thumps. either after I've
eaten or walking up stairs but not so much after light exercise =
Walking and swimming. I have digestive problems and diabeties and
high cholesterol. ive had several normal ecg and my gp says my blood
pressure is ok; usually around 70-80 over 130. I use to suffer from
panic attacks and i am on medicatiin for depresion. i recently had a blood

test that indecated infection. i dint sleep very well and i am easily tired.
For the past 4-6 months my muscles have been aching and cramping. i some