Dude, marriage is tough. Med school is tough. They absolutely won't cancel each other out. Trouble in one will without a doubt make things tougher in the other.
Is it hopeless? Nope. Will making it work requre a lot of hard work, stress, sacrifice, etc.... Yep.
Look, you say you are the one who has been doing all the work to hold things together. I bet if you could read your spouses mind, she may be thinking she is the one doing all the work.
If you go into marriage with the attitude that both partners contribute 50%, it is doomed to fail. You have to have the attitude of "I'll contribute 100%." If your partner also has that attitude, then things might just work out.
The reality is that if you think you are contributing 100%, and are really giving it your all, you are probably in reality only contributing 60 or 70%. Same goes for her.
If you give less, your partner will feel resentment, regardless of how much she is giving. If she gives less, you will feel resentment. Once either feels resentment, the natural tendency is to say "To hell with this. I've been giving 100%, and getting nothing in return. I'm gonna give less. I'm just gonna give 50%. He/she will have to meet me halfway."
Unfortunately, when you give what you perceive to be 50%, it is actually probably closer to 30%.
As you can see, a viscious cycle is developing here and the only possible outcome is a failed marriage.
If your marriage matters to you, you need to examine your own actions. You need to say to yourself "I'm going to give 100%, no matter how much she gives."
You need to think back to the time before you were dating her. Think back to the time when you were trying to get her interested in you. Think back to when you were trying to win her heart, to make her fall for you, to make her fall in love with you.
If you aren't currently doing those same things at the same level of intensity, that you were doing at that time, then you are not giving 100% to this marriage.
I'm not saying she is giving 100%. I'm saying that unless you do, she won't.
Unless you do give 100%, regardless of medical school, your marriage sounds doomed to me.
You are going to face stress, long hours, hard work, fatigue, and cute nurses who flirt with you all the time.
Is it any wonder so many doctors cheat on their wives and end up divorced?
It doesn't have to be that way though. There are plenty of doctors with the maturity to recognize all of the above and take appropriate actions and avoid inappropriate actions.
The choice is really yours. I'm not trying to be hard on you, just honest.
I wish you the best of luck in both your marriage and your medical career.....in that order!