Anythony-- yikes!! You sound like you are about to drive a Ferrari into a brick wall at 160 mph. You need to take a few steps back and seriously evaluate what is going on in your life. If you don't get things straight you are either going to drop dead out of nowhere or suffer some event that will forever alter the course of your life (such as a stroke or heart attach or brain aneurysm).
So, yes stress can and does kill. Your body can handle stress, but in short, unfrequent bursts, but not continuously, 24/7 - what you are doing to your heart now. Your body must be toxic right now and your adrenals are on constant overdrive, which means your cortisol levels are probably too high, and in this constant state, it can cause cancer. Lack of sleep can also kill over time. I read one time about a study they did where they did not allow mice or rats to sleep for 2 or 3 days and they died. The body needs sleep in order to rejuvenate - the brain is kind of "restarted/rebooted", the muscles and nerves recover and your blood pressure is lowered and your heart is under less stress giving it a rest. If you are cutting your body so short on sleep as you are you are not allowing your body to recover and do these things I mentioned and therefore the body cannot perform as it's supposed to. you are like driving your car without oil and as your know this will break down the engine and cause it to fail eventually and eventually your body will fail you.
Really, believe it or not, the adult body needs a solid 8 hours of sleep a night to do the things it needs to and you are not even getting half of this.
You can do a number of things to control stress-- first you need to get adequate sleep. if you have insomnia, you probably need some drugs to help you sleep. You also need exercise , which should help you sleep and also will help you control stress. Other things are meditation, doing something that relaxes you and also sex can lower stress in a healthy relationship. Good interpersonal relationships and good external environments also help lower stress. If it's your job that's causing so much stress or a family situation you should seriously consider making major changes.
So, get to a doc pronto to see if you need the drugs to sleep and see if you are allowed to do the activities that I have outlined and if you get permission for them, start participating in these activies once you get some solid rest. And once you do, you need to continue to get a good night's rest. Back when most people in the US were farmers and when we didn't have all of our electric lights, TVs and the Internet, most people slept 10 hours per night! Amazing huh!?!
But, 3 hours a night is just not gonna cut it. I've pulled many all-nighters in college and sometimes in my career have all-night work sessions (aka burning the midnight oil) and know I feel terrible for 2 days after that-- like a zombie. I don't know how you can even continue in your state. If you don't kill yourself if you don't change, you will end up killing someone else like falling asleep behind the wheel or driving past a red light or something. When I was in the Navy, if a sailor did not get adequate sleep, they are not authorized to work with heavy equipment. it's no joke-- that is lack of sleep. Why do you think elite athletes, astronauts consistently get adequate sleep? You can't perform at elite levels without adequate sleep. I read about some long distance runner training for the olympics-- his coach orders him to get 10-12 hours of sleep per night. All he did was run, sleep and eat up in the mountains. It gives his heart plenty of rest so when he does train, he can push his heart to its limits. That's the philosophy. In your sleep deprived state you are probably only working at 25% of your physical and mental capacity of you are lucky.
If you don't change this downward spiral, you will probably end up with a catastrophic heart attack or major stroke and then you will never be the same after that if you survive it. If it's not that, the cancer will get you. Besides all this, you are living a miserable existence. You have a choice, change or face the consequences. It's not a matter of it, but when. If a train was coming at you, wouldn't you get yourself out of its path pronto? Well this is no different, perhaps worse because I'd rather be run over by the train in an instant than be a vegetable in a hospital bed the rest of my life.
Get to a Doc ASAP and work with him or her to come up with a long-term care plan and then stick to it like glue!
Are you under a doctor's care? The high BP and and cholesterol needs to be controlled. If you are getting symptoms like blurry vision it's very concerning.
Have you had a TSH (thyroid stimulating hormone) test? The sleep deprivation, high BP, high cholesterol, anxiety etc can all occur with thyroid problems.
If you had anxiety alone, without the clear risk factors, it would be of less concern-though certainly not entirely without it.
Please see a doctor as soon as you can.