Break ups are (most) always difficult. It sounds like perhaps the timing of your relationship wasn't good with so much outside stress over course work etc.
The truth is your boyfriend lost the feeling. It happens. You can spend your time replaying what happened in your head (that's normal) but you should also take the time to process what you said about the self sabotage part. That is very real and happens all the time in relationships - and will continue to happen for you unless you learn from this experience and don't repeat the same pattern the next time around with a new guy.
He probably is sad that it didn't work out and has been feeling depressed and listening to sad music. Maybe he leans towards anxiety and depression anyway and the add 'stress' of doing the right thing to keep a girlfriend happy plus his course work was too overwhelming for him and he needed to make a change.
One bit of advice I'd offer is that when the next relationship comes along.... and that will happen..... don't let it get so intense so quickly. I have found that the quicker you get involved in a relationship - being romantic or just a plutonic friend - the quicker it seems to fizzle out. Go slow, let the relationship gradually grow, take your time getting to know each other..... let it build. Very few people marry the first person they get into a relationship with - it does happen occasionally, but rarely. It will take time but you will get over this and grow from it and be a better partner for the next time. The relationship is done though and I don't believe he will be coming back around. You are wise not to contact him and just move forward and learn from this experience.
Best of Luck!