bubble feeling going up arm, lump over vein

Im not sure if im in right area but any advice would be appreciated.
On my left arm, in the crease by the elbow over the vein to the right of arm, I have a lump. It grows. At some points it is smaller and other times it seems to get bigger. I have gotten a stabbing shooting pain in my elbow. That pain has happened maybe 6 or 7 times. I have had this for around 7 months. Around that same time i was lying in bed, falling asleep and I felt a bubble type feeling going up my arm. It was really weird and i didnt know if something was running up my arm or if i was dreaming or imagined it.
Anyone else have this type thing. The bubble feeling took like 5 seconds and went up my arm and i haven't felt it since but i have a lump over my vein in arm crease now.
I dont know if it could be related but I also have a appt for cardiologist as i did a drug study and something came up on heart monitor and i get chest "pain" more like pressure and light headed. I do have appt booked for heart but am wondering if the lump is more than a cyst. Thank You