I have had problems with my vision, balance and heart rate for a few years. Sometimes I literally feel like my body is just going to give out and die.?

Check your BP. Sounds like circulatory problems. You need a complete physical from an internist..
Cardiac check. You should consider having your heart and long term blood sugar checked. Depending on your age, you may be showing signs of atrial fibrillation or psvt, both can be dangerous. Vision and balance problems could be a result of high blood sugar over time or multiple sclerosis.