Don't even bother looking at the russian sleep experiment, as stated above it's a scary campfire story. @sanitystruggle is correct. Unless you have an extremely rare medical condition or are being tortured with war crimes, you are eventually going to fall asleep. Your brain is already likely taking micro sleeps you aren't even noticing.
As far as your heart rate being high, yes it's possibly related, however if you are consuming caffeine or other stimulants and/or are dehydrated then it's going to spike your heart rate. 120 is an elevated heart rate but not elevated enough to cause any doctor to be too concerned or treat you with anything more than a bag of fluids.
My suggestion would be to drink some water and go to sleep before you start hallucinating. Check your heart rate again after you've slept and are well hydrated. If it's still elevated and you feel concerned talk to your GP.