Does this sound like part of an anxiety disorder?

Many nights when I’m trying to sleep (including last night), I can’t because I’m afraid my heart still stop beating for some reason. I’m a healthy person so I don’t know why I think this, but It keeps me awake awhile because I worry that if I keep thinking it will stop than it will. I don’t know if this is really something wrong w/ me or not.

It definitly could be. The symptoms are listed below. I have anxiety disorder myself and it is easily treatable. If you can’t afford a regular Dr. call your county social services department (or what ever they are calling it) They should have a free counseling service available and probably can help you with medication costs too.
Generalized Anxiety Disorder (GAD)

What is Generalized Anxiety Disorder?
Generalized Anxiety Disorder, GAD, is an anxiety disorder characterized by chronic anxiety, exaggerated worry and tension, even when there is little or nothing to provoke it. more>>
Signs & Symptoms
People with generalized anxiety disorder can’t seem to shake their concerns. Their worries are accompanied by physical symptoms, especially fatigue, headaches, muscle tension, muscle aches, difficulty swallowing, trembling, twitching, irritability, sweating, and hot flashes

“I always thought I was just a worrier. I’d feel keyed up and unable to relax. At times it would come and go, and at times it would be constant. It could go on for days. I’d worry about what I was going to fix for a dinner party, or what would be a great present for somebody. I just couldn’t let something go.”
“I’d have terrible sleeping problems. There were times I’d wake up wired in the middle of the night. I had trouble concentrating, even reading the newspaper or a novel. Sometimes I’d feel a little lightheaded. My heart would race or pound. And that would make me worry more. I was always imagining things were worse than they really were: when I got a stomachache, I’d think it was an ulcer.”
People with generalized anxiety disorder (GAD) go through the day filled with exaggerated worry and tension, even though there is little or nothing to provoke it. They anticipate disaster and are overly concerned about health issues, money, family problems, or difficulties at work. Sometimes just the thought of getting through the day produces anxiety.
GAD is diagnosed when a person worries excessively about a variety of everyday problems for at least 6 months.13 People with GAD can’t seem to get rid of their concerns, even though they usually realize that their anxiety is more intense than the situation warrants. They can’t relax, startle easily, and have difficulty concentrating. Often they have trouble falling asleep or staying asleep. Physical symptoms that often accompany the anxiety include fatigue, headaches, muscle tension, muscle aches, difficulty swallowing, trembling, twitching, irritability, sweating, nausea, lightheadedness, having to go to the bathroom frequently, feeling out of breath, and hot flashes.
When their anxiety level is mild, people with GAD can function socially and hold down a job. Although they don’t avoid certain situations as a result of their disorder, people with GAD can have difficulty carrying out the simplest daily activities if their anxiety is severe.
GAD affects about 6.8 million adult Americans1 and about twice as many women as men.2 The disorder comes on gradually and can begin across the life cycle, though the risk is highest between childhood and middle age.2 It is diagnosed when someone spends at least 6 months worrying excessively about a number of everyday problems. There is evidence that genes play a modest role in GAD.13
Other anxiety disorders, depression, or substance abuse2,4 often accompany GAD, which rarely occurs alone. GAD is commonly treated with medication or cognitive-behavioral therapy, but co-occurring conditions must also be treated using the appropriate therapies.

http://www.nimh.nih.gov/healthinformation/gadmenu.cfm

What Is Social Anxiety Disorder?

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