These symptoms of yours do not denote any life threatening illness. They are not related to any organ system problem or pathological process, so you should not be worried at all. Relaxing yourself, deep breathing, listening to some music, watching TV may help you. If one start thinking about serious illness or disease process, one can get too anxious and panicky. I would suggest you, not to worry at all, do not think about them, as they do not fit any disease process.
Please feel free for your follow up questions.
Fast twitching pulses in the body can occur due to increased caffeine consumption (drinking lot of caffeine drinks), due to the medications or electrolyte balance etc, but with breathlessness and pain in abdomen (all of the three are different organ system), this would denote panic reaction or anxiety, as these symptoms do not correlate to each.
A sudden high blood pressure and low pulse would warrant (if you are taking it by your home instrument), confirmation by a mercury instrument or another instrument. The anxiety can cause high blood pressure. If you have been diagnosed hypertension (high blood pressure) by a physician, you should regularly take your medicine and keep checking it regularly. An occasional increase would warrant change in your medication. If you have not been diagnosed hypertensive patient, an occasional rise can occur, as I mentioned with the anxiety. Still if this recurs, you will need some kind of medications, so this is controlled.
Taking the missed antibiotic dose together would not be right. A gap of around 4-6 hours would be minimum, if you are taking an antibiotic which is to be taken twice a day. If you get up in night, you can take that dose. A 210 blood pressure is high and your doctor should find reason for it. If this is frequent, you will need medicine, but for that, you should not be worried now. Though, if this high blood pressure occurs, a medical consultation should be sought.