Should I pursue a PhD if I am clearly not qualified for it?
Nothing has said that you're not qualified to be a researcher—getting good grades and being a good researcher are not entirely correlated, and having the skills for one is not necessarily a guarantee of success for the other. 

What your comments suggest, though, is that you would likely not enjoy the process of getting a PhD. Given how long it takes to get a PhD, that's an awfully long time to spend being miserable.

So ask yourself:


  What is it that I enjoy about research? Is it enough to justify all the drawbacks it would bring?


If you can't justify getting a PhD to yourself, don't make yourself miserable by forcing yourself to do something you don't want.