Well because your heart beat is increasing very rapidly your hearts output will speed up or increase. This happens because the heart is beating faster forcing it to pump blood threw you at a more efficient or higher rate. This increased flow of blood is very important for your lungs because with an increased heart rate comes increased breaths meaning your lungs are relying on that blood flow to be able to release oxygen into your fast flowing blood stream. Which that oxygenated blood will then fuel the rest of your body. Sorry if this is kinda a mess but pretty much the main idea is your body needs an more blood flow per minute because it allows the rest of your body to function as fast and efficiently as your heart.
depending on what type of messages like things that are very worrying and contain things like your adress and hassment then i would say take it to the police but if they are just being perves and being annoying blocksss themmmm
