Sending a link to your profile page through Grabify is a bit odd, indeed. Potentially, clicking on such a link could get your account hacked if one of the two following is true:
- You did in fact not end up on Facebook, but on a phishing site mimicing Facebook, and you entered your password there.
- There is some sort of vulnerability on Facebook. Getting the victim to click a link is a common prerequisit for exploiting many web app vulnerabilities.
I can't comment on if the first one is true or not. The second one, though, is unlikely. Sure, there has been vulnerabilities in Facebook. But on a big site like that they get fixed quickly. The chanse that your boyfriend would be using an unkown Facebook exploit against you is pretty low.
What you can do, just in case, is to change your password and log out all current sessions.
By the way, I wouldn't call you an idiot for clicking on a link your boyfriend sent you... I would have done the same.