Long post!!- diarrhea and heart palpitations?

It started last night. I was sitting in the car when randomly my heart just went "boomboomboom" really fast and hard like I could feel it in my chest. Then later that night at 4 am I woke up to SEVERE cramping like I needed to poop and was going to have diarrhea but I swear nothing has ever hurt so badly. Diarrhea sucks but this was on a whole new level. i was lightheaded, ears ringing and getting cold sweats. 

I didn't go that much, so there was no relief and I was yelling in pain for a half hour until I actually had real diarrhea. This lasted like two hours. It subsided and I was able to fall back asleep. I then woke up at 7 am and didn't have any more cramps except I do now but there's hardly anything left to come out, it just hurts. And every time I get off the toilet it starts hurting again but I sit down and nothing happens most of the time just a few times. 

Idk if the heart thing and diarrhea are related but idk if I should see a doctor especially if I'll have to pay out of pocket and I'm not sure what they could really do. But I'm still getting those diarrhea cramps just not as intense. although once there was a tinge of a bloody mucus thing but I'm positive it did not come out of my vagina so I didn't freak out.  I do have a history of heart problems in my family so I was referred to a cardiologist but can't go until I get back to where I live when I'll be 23 weeks. I'm 19 weeks.  I have felt the baby move here and there while this was happening.