GI Disorder and Internal Shaking

Hi all. I'm a 21 year old South Asian female and I have been having GI issues for about five years--mainly along the lines of constipation. I do have bowel movements every day but it takes a long time & I am rarely fully cleared out. These GI issues are always accompanied by other health issues (gas, pressure in head, etc). Recently, some scary new conditions have manifested: In the past few weeks, there have been times where my heart starts beating wildly and very fast. Sometimes, when I'm tired and constipated, my entire body feels like its vibrating internally; the shakes aren't visible but it feels like all my muscles are quivering. At this point, I feel a constant shaking/quivering within my body, especially in my heart cavity.

I have had TWO EKG's and both came back normal. All lab tests for diabetes, hypertension, cholesterol, etc came back within normal limits. I am very concerned about this internal shaking. My dad says he found something about how GI disorders can impact muscoskeletal system and since the heart is a muscle, it's contracting and being affected. But I wanted to know if anyone here can help!!!!!!! If anyone knows anything at all please please please let me know!!!!!