I have this tight feeling in my head that comes and goes and it makes my body weak?

Many possibilities: Low blood pressure and hypoglycemia are possible causes. If you are overweight you might have increased intracranial pressure that comes and goes. For all these problems you could avoid tobacco, alcohol, processed food and eat 6 small equal meals, with raw fresh vegetables, fruits, and high quality protoein, good essential fatty acids, get 7-8 hours of sleep, move rhythmically and manage stress.