Brief Answer:
Anxiety plus migraines plus GERD

Detailed Answer:
Thank you for asking
COnsidering your young age and no previous history of any cardiac or vascualr history , i think this sudden barrage of symptoms hardly remaining for a few minutes and self resolving is most likely an anxiety and psychiatric issue and doe snot seem like an organic one.
Anxiety and stress can cause migraines headaches and they may present as numbness, palpitations are also psychological and anxiety related.
Let me discuss some other odds.
Providing your history your labs are clear like EKG and echo etc so that clears the cardiac issue.
Now assessing thyroid functions would be wise to rule out any metabolic issue like hyperthyroidism as that may cause this palipitation.
GERD / Acid reflux may also cause this and if any Gi symtom of GERD then that needs to be addressed and may resolve the symptom.
Sudden cold hands and extremities are classic for anxiety but to be on the safer road and assess the vascular status and rule out any hyperactive sympathetic functioning troubles like raynaurd's phenomenon would be wise , More if the symptoms are after exposure to cold etc.
Smoking itself may cause such cold extremities, so quitting that would be wise.
I will repeat, to me its a psychiatric profile and anxiety and panic attacks are the only valid explanation for connecting all the symptoms, but there is no harm to get evaluated for any trouble which i would say is least likely to show any positive finding.
Get GERD and Migraine Prophylaxis meanwhile and see if it helps.
Here are some tips for GERD and see if it helps
Lose your weight. If your BMI is 25 or above you need to lose weight. Calculate you BMI Here http://www.nhlbi.nih.gov/guidelines/obesity/BMI/bmi-m.htm
Alcohol ? say no to it. Now is the time. Get sign up to Alcohol Anonymous and seek help to gradually resolve this addiction. Booze will ooze the health out of you.
Coffee,Chocolates, citrus juices, tomato based products like ketchups, sauces, pastes etc, Peppermints, all the onion family, beans are some of the diet you need to avoid to relieve symptoms.
If you are fond of eating, time to stop it. reduce diet intake, instead of increasing the quantity, increase the frequency, 5 times short meals instead of 3 bigger ones will be better.
If you sleep just after or with in 3 hours of meal intake, this habit needs to be stopped. Increase the interval.
When you sleep, elevating the head side of the bed at least 8 inches would be a good addition to the plan to combat GERD.
Bending and stooping and upside down hangings with all other unnatural postures need to be avoided.
If the above mentioned precautions are not enough to get you out of the trouble then you need to opt for medicines. Never try to self medicate yourself. Remember every drug is a poison and every poison is a drug. SO seek the gastroenterologist or primary care provider for this and let it be there business. Proton Pump Inhibitors, Histamine receptors type 2 blockers, Pro kinetic agents like aluminium hydroxide and ant acids would be the list of medicines to opt from.

For migraine here are some basic tips.
avoid factors that precipitate a migraine attack (eg, lack of sleep, fatigue, stress, certain foods, use of vasodilators).use a daily diary to document the headaches. This is an effective and inexpensive tool to follow the course of the disease.discontinue any medications that exacerbate your headaches. If an oral contraceptive is suspected to be a trigger, you may modify, change, or discontinue its use for a trial period. Similarly, if hormone replacement therapy is a suspected trigger, should reduce dosages, if possible. If headaches persist, consider discontinuing hormone therapy.
Biofeedback, cognitive-behavioral therapy, and relaxation therapy, occipital nerve stimulators,FDA recent approved Cerena Transcranial Magnetic Stimulator (Cerena TMS), are some non pharmacological approaches which help the migraines.
Use some preventive agents (eg, frovatriptan) perimenstrually as most of the migraines in women are associated with menstrual cycles.
SOme CAM (complementary and alternative medicine) techniques have been proved effective too.Biofeedback and behavioral therapy, herb butterbur (Petasites hybridus),riboflavin (vitamin B2), magnesium, and feverfew,coenzyme Q10 (CoQ10),Melatonin,Body work - Eg, chiropractic, massage, and craniosacral therapy,Nutritional/herbal supplements - Eg, vitamins and herbs,Acupressure and acupuncture, yoga etc are some of the level 1 recommendations by XXXXXXX college of neurology for these migrainous headaches.
Some dietary triggers which trigger migraine need to be avoided.Common dietary triggers include the following:
Alcohol - Particularly wine and beer
Caffeine overuse or caffeine withdrawal
Chocolate
Aspartame - eg, NutraSweet and Equal
Monosodium glutamate (MSG) - May be found in Asian food, canned soup, frozen or processed foods, and the seasoning product Accent
Fruits - Citrus fruits, bananas, avocados, and dried fruit
Nuts - Peanuts, soy nuts, and soy sauce
Tyramine, a biogenic amine that accumulates in food as it ages, may provoke migraine. Sources include the following:
Dairy - Aged cheese
Meat - Bacon, sausage, luncheon meat, deli meat, pepperoni, and smoked or cured meat
Pickled foods
Heavily yeasted breads - Eg, sourdough
Vinegars - Especially wine vinegar
Some types of beans
exercise for migraine prevention (40 minutes 3 times weekly for 3 months) has been proved effective.,Tonabersat,Transient receptor potential vanilloid type 1 antagonists,Prostaglandin E receptor 4 receptor antagonists,Serotonin 5HT1(F) receptor agonists and Nitric oxide synthase inhibitors are some of the novel managements for the migraines these days.
I hope it helps.
Take good care of yourself and dont forget to close the discussion please.
may the odds be ever in your favour.
Regards
Khan

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