If you are having a hard time choosing, you really are not ready to commit to anyone right now. Anything that has to be decided NOW is not a wise choice.
The fact that you mention that your boyfriend treats you with respect and listens to what you have to say and does everything in his power to make you smile makes me wonder if the doctor treats you with far less respect. The pressure he is putting on you suggests he is like most doctors... they think they are God and you are privileged to be near him.
Also, life with a doctor is a LONELY life. Is financial stability worth living a cold, bleak existence? If financial stability is your main concern, get more education and a better job.
Your boyfriend is still working toward his future (very hard, it sounds). If you let him go, he will have a broken heart, and the girl who helps heal his heart will probably be a very blessed young lady.
I think you need to get a different job. I think if your boyfriend is under the impression you are committed to him, you might need to let him know you are not really ready for a serious relationship right now.
If the doctor pursues you and you REALLY care about him, make him wait at least a year so you can truly get to know him better. In the course of a year, his true colors should come out strong enough for you to know the truth about whether you really want him for a lifetime or not. If he refuses to wait, he will cheat on you after marriage, because he is only concerned with his own desires and your well being and happiness are not important to him.