Weakness and tiredness can be because of various reasons like
vitamin d and
b12 deficiency. There can iron deficiency or
thyroid related issues.
So do the following blood tests:
CBC, Iron profile, Thyroid Profile (Free Blood), 25-OH Vitamin D and
Vitamin B12 Assay.
Also Monitor your Blood Pressure.
For the time being take plenty of fluids. Keep yourself hydrated. Drink 3-4 litres of water everyday.
Once you get the blood reports.. the medications can be provided depending upon the results.
You can also ORS powder: Mix the whole packet in 1 litre of water to be consumed within 24 hours.
Keep monitoring.
Next Steps
Consult under Practo in case of emergency