Excel not responding and freezing

Vmitra9 

I have a workbook where I analyze stock data of last 3 years, I has kind of heavy amount of formulas and calculations, whenever I made any change to this workbook, it got crashed, excel not responding and eventually freezing. 

maybe using that much formulas isnt the best practice, then i made it lesser calculation and formula intense, then it worked charmingly.

This should not come as a surprise. Can this approach not be your solution, given that "it worked charmingly"?

should I use power query, will that can take load of huge datasets

That's hard to say, given that we don't know the nature of the analyses that you're doing. You're not telling us enough to even make an educated guess....