Brief Answer:
Lyme disease or a UTI

Detailed Answer:
Thank you for asking

Migraines are rarely associated with shivering and chills and fever. Recent travel and age of 60 makes the possibilities fo an infection more likely. Urinary tract infection is on the top. a simple urine routine exam would make sure of that. Recent history of travelling makes it more likely.

Next possibility would be some tick bites or mosquitoes bites and malaria suspicion or lyme disease suspicion would be considered but rash would be next thing to look for as lyme without rash is like pie without key lime. Not possible. Also low grade fevers are the cons and discouraging symptom for that.

Consult to an infectious disease specialist would be wise. But first thing first. A urine routine exam would be wise to sort out. Followed by a full blood count to sort out any infection.

Rest as far as migraines are concerned here is a detailed management which is least likely a cause of your recent symptoms.

Migraines are the common cause of recurrent headaches and family history of this issue makes it more likely.
I want you to know that Migraine treatment involves acute (abortive) and preventive (prophylactic) therapy. Patients with frequent attacks usually require both. Measures directed toward reducing migraine triggers are also generally advisable.
Acute treatment aims to reverse, or at least stop, the progression of a headache that has started. Preventive treatment, which is given even in the absence of a headache, aims to reduce the frequency and severity of the migraine attack, make acute attacks more responsive to abortive therapy, and perhaps also improve the patient's quality of life. An overview of migraine treatment is shown in the image below.
Migraineurs should be screened for cardiovascular risk factors, which, if present, should be aggressively treated. Migraineurs with aura should also be counseled on the increased risk of stroke with smoking and oral contraceptive use.
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 you see the depth of it. Discuss all the possible options with your doctor and let them select what is best for you. COnsult your neurologist and hope for the best.

Nut shell , Seek an infectious disease specialist and let them take care of you.

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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