I’m in a similar position to you in terms of commitments. Balancing work and college is a challenge in itself, and it’s difficult to add a hobby into that mix without letting the people in your life slide. One of the big challenges with education IME is that the workload is pretty unpredictable. I never know how much stress you’re walking into that week or how much time I have available, which is sometimes at odds with a typical plan based around a 9-5 work week.
I try and make things easy on myself- I set up my training space ahead of time, lay my kit out, etc. Cuts back on some of the time spent messing around, which adds up. I think it’s also worth speaking to your girlfriend and setting aside a couple of time slots per week to train- if people know ahead of time I think everything runs a bit more smoothly, and intentionally scheduling time to do something for yourself each week is something I would recommend to anyone from a general health/wellbeing perspective. I also let my partner know ahead of time when I have a recovery week and we usually plan something ‘special’ together- usually just little stuff like the movies, but I try and go out of my way because training sometimes takes up a little too much of my time/energy 
Planning and communication can go a long way!
And finally, don’t beat yourself up! At the end of the day we’re all doing what we can with what we have, and something is always better than nothing even if you’re not always able to stick to the plan. It sounds like you’re working super hard, so don’t stress if you need to take a step back from training, especially if you’re in unfamiliar circumstances. Those fitness gains will always be there for when you get back into things 