Off to Med School, tough girlfriend/family position

[MEDx]

Hello everyone,

I would really appreciate your advice because I'm in a difficult interpersonal spot. I will start medical school soon at one of the best schools in the US, but I have one last thing I need to address: My girlfriend. I know my ideal situation would be to not encumber my twenties with a relationship when I am still trying to grind/become better personally and professionally. I've had three conversations to smoothly end our relationship, which would be a long distance relationship if it were to be continued into medical school.
My problem is she has deflected every conversation and continues to monopolize my time; I also think she's clinging to this relationship because of my potential long-term provisioning capacity by how she talks about my becoming a doctor. I currently live with my family, who loves my girlfriend; my sister, who is not mentally stable, has practically made my girlfriend her best friend because she does not have many friends. If I broke up with the girlfriend, I'm also afraid my sister (8 years older than me and also living at home) will go absolutely crazy, and it would not be safe to live at home (e.g., she's threatened to kill her fiance over something incredibly minor). My dad (parents are divorced) advised me to go to med school and break it off at that point with something along the lines of "This isn't gonna work out." What do you think is the best course of action?

TL;DR: Going to med school, girlfriend resists breakup conversations, breaking up will incite chaos and possible violence in the home. Should I wait until I start med school to break up?

Any constructive feedback would be greatly appreciated.

 

[Von]

Go to Med School.

Tell your Girlfriend to come with you (if you want her)

However, I feel you dont want it anymore. So here:

Go to Med school

Tell her you'll have a LDR (long distance)

Let nature take it's course (she will want to break up because it aint working due to the distance and she dont see you... So your sister will have her friend, your gf an impression of relationship, you will have Med school)

Schedule precise date time over internet (cause you busy)

Eventually she will understand

 

[Spaz]

Don't break off. Any sudden death of a relationship will hurt.

Let it die a natural death, it's something both of you could live with and have closure.

Go to med school.

Continue as if nothing happens, keep in touch with your girlfriend when you are away at school, it's likely that your girlfriend will wander off in a year or 2 and she'll initiate the break.