This is a difficult predicament to be in. My first question for you is, did you think you wanted to be in medicine prior to it getting tough? That is, you need to really decide if this is a case of you wanting to quit because the going is a little harder than you expected, or, is this really something that's not for you? This is a very important question. You will always have adversities to face in life. Running from a difficulty is not the way to learn to deal with it. You have to learn to tackle these things, head-on.
If you've already had that conversation with yourself, and you think medicine REALLY isn't for you, then there are family/cultural issues to face. If you quit, is it simply a matter that your mom will no longer fund your education, or, will you be forever shunned by the family? While we might think, "oh, I don't need them," it gets mighty lonely during the holidays with no place to call home.
Is there some aspect of medicine that you can go into, rather than being a doctor? Perhaps Radiology, pathology, etc? I know some sales people with medical backgrounds - they sell things like neurostimulators, medications, etc, and are very successful. Perhaps finding a related field will keep both your family and you happy?
I do NOT advocate taking a career that you do not want, simply to keep peace in the family. But, you need to understand the potential consequences, including financial, and be prepared to address them. I recommend you seek out a school counselor and discuss this with them.
I wish you the best as you try to sort through this!