My husband and I have lived together in a shared 2-bed apartment all through medical school, even before we were married. We got married this past June and my husband is an M3. Living costs are a challenge for sure. I was in grad school for about the first 1.5 years of medical school so we were both living solely off of student loans with no financial help from our families. Now that I'm working FT and have been for almost a year it's a little better but I carry the financial burden. My husband covers the rent and utilities, our shared credit card payments best he can with me but the end of the loan cycles are particularly challenging and I end up paying all rent, utilities, and bills for like the last month of 2 of each cycle because he's out of money... about 4-5 months or so of the year.
We got married this past year in June and paid for it on our own which was another financial burden. However, we had a very small wedding so it was a lot less expensive than an average wedding but still pricy for a one-income household. And I work in public health so it's not like my income is huge.
Depending on if you're getting financial help or not, consider combining as many expenses as you can... utilities, apartment, a car even. (My husband and I share a car which helps alot. We live close to the school). Apply for scholarships too. My husband has gotten a few over the years thankfully and used a scholarship this past year to help pay for my engagement ring.
Paying to LIVE through medical school is really stressful, I'd recommend with you both being really busy to try to set aside time 1x/month to go over expenses and bills and try to be as smart with your money as best you can. As the non-medicine SO I manage all of the bills, expenses, cleaning, cooking... everything. I can't imagine it if I was in medicine too. Not that working FT or being in an expedited graduate program as the SO were easy but it's not quite the same. Just make time to assess your finances together, see where you can cut corners and where spending your money is the most beneficial (paying for food at the hospital vs cooking) things like that and the cost of your time. You can also use the holidays to ask for things that would help you like maybe some gift certificates for a cleaning service for your house or some grocery gift cards to help curb the edge. Little things like that are great!