Should I apply to graduate school in philosophy?

This question is not one I can answer for any individual student. Making an informed decision about applying to graduate school involves an (1) honest assessment of your own aptitude, (2) tolerance for independent work, (3) persistence in the face of difficulty, and (4) willingness to spend a long time on the job market.

You'll want to solicit the opinion of your professors, talk to graduate students in the departments where you want to study, and reflect carefully on your strengths and weaknesses, in consultation with your professors and friends.

You might also want to look at blogs like The Philosopher's Cocoon (for early-career philosophers) to get a sense of what it's like to be a professional philosopher--which is the usual aim for people getting a PhD in philosophy. You might also try following philosophers on Twitter and other social media--with the caveat that social media often makes extremes most visible (strong reactions pro/con).

Getting into graduate school in philosophy is difficult; getting a job in philosophy is even more so. Keep in mind that your professors are the ones who have succeeded in getting a job, out of a number of people who did not--so just because they have managed to get employment doesn't mean you will. Be aware of the financial and personal risks involved before you move forward.

I find being a professional philosopher quite rewarding! But it's a difficult path to a job, and I don't encourage students to apply to graduate school without awareness of this fact.

Another professor (Michael Huemer) answers this question, largely in the negative, here.