Wa Alaikum Salam. Yes, AL HAM DU LILLAH I am fine and doing Great by the Grace of ALLAH ALMIGHTY.
Now that's a serious issue. Please get your electrical systems, Alternator (a.k.a Generator) and other related stuff checked by some good and reputable Electrician, so as to find the exact cause and also that why battery had to be replaced 6 times in 03 years? (i.e. on the average, 01 battery after every 06 months).
If everything works fine and battery is taken good care of, then it easily lasts at least 02-03 years!
Please refer to following post above:
Check the items one by one, and do the needful; air filter (along with AC / Cabin filter too; not related to fuel efficiency, but good health of passengers), Throttle body, MAF sensor, spark plugs, catalytic converter, concerned sensors (i.e. scanning via computer, to find any / all error codes), Tire pressure, wheel balancing / alignment, etc.
Replace all fluids, oils, etc. if not done recently, and always use recommended grades.
Do also check for fuel injectors, and fuel pump, fuel filter, etc.
I do not know whether you own 1.0L, 1.3L or 1.5L Vitz, however, if you have 1.0L Vitz, then it has 03 cylinder 1KR-FE engine, which is notorious for knocking and vibration issues. For causes of engine vibration, following video may prove helpful:
Do specially look for engine mounts. If excessive vibration is due to engine mounts, they might be requiring replacement.
Any oil above 5w-30, and lastly 10w-30, is "Zehr-e-Qatil" for 1KR-FE. Good! 
You got rid of 10w-40 ASAP.
Only use fully synthetic 5w-20, and lastly 5w-30, with API SN / SN +, with RC, and / or ILSAC GF-5, preferably after complete engine flush.
Lahore is my hometown, but now being in Islamabad, I regret, I may not be able to guide, however, lets ask respected members from Lahore.
@haseeb.basharat @fastian04 Brothers kindly help the fellow member regarding best workshop in Lahore, which can do all sorts of works for Toyota in General, and JDM Vitz in particular.
