Re: job prospects, there are very little (if any) career paths in law that would look favourably upon a med degree. You won't be disadvantaged, of course (except that you will lack the experience that your fellow law students will have, because while they're out getting internships you're still stuck at uni in your med degree), but your resume won't be any more attractive.
Unless you were going for an extremely niche job (I don't even know, maybe in-house lawyer for a hospital? Even then, your med degree will be next to useless. I honestly cannot think of any examples), you're frankly wasting your time and money. And for what? Bragging rights?
The only time I can see a law degree being useful to a doctor is if you were sued for malpractice, and generally lawyers are discouraged from representing themselves anyway.
Also, if you like English then do arts majoring in English. Being good at/interested in English has no correlation with success/interest in law.