The details of your heart and BP issues are not the typical presentation for autonomic dysfunction, so I don't think that is your problem. In most cases the heart rate includes tachycardia and even bradycardia...but both are quite pronounced, not an every now & then thing. And the BP isn't usually high. With autonomic problems, it drops (considerably--like over 20 mm Hg systolic) upon standing as the body is unable to compensate for changes in position.

The GI problems associated with autonomic dysfunction are most often motility related...delayed gastric emptying.

I really have to agree with MrsD on this...that your gallbladder issue may be t the root of your current problems (not everything, but at least the recent exasperation). When are you getting this surgery? I think (and hope) you will notice a big improvement once this surgery is behind you.