Projecting is one of the defense mechanisms we humans have. It is easier for our mind to shift the blame of our unhappiness (or something else) onto someone else's shoulders, rather than accept the hard reality and our own fault. When we shift the blame on someone else, it is much easier to keep our own self-image intact and consequently lessen or eliminate the emotional burden. Probably the scariest thing in defense mechanisms is that they are usually automatic - we act and utilize them in autopilot; the realization of a defense mechanism activation may never be noticed consciously unless the person understands their own emotions and behavior. Even the most emotionally strongest people utilize defense mechanisms to cope with sudden emotionally taxing situations in life. There are good ones (e.g. automatic realistic reframing of someone else's behavior: say for example your boss is yelling at you and you automatically think they are having issues in their own life rather than concluding it being a flaw on yourself/them hating you) and really bad ones (e.g. externalization: you get a bad grade in an exam and you directly blame the teacher, the school, the material or something completely irrelevant factor - projection is one of externalization's forms).
So, next time you see him angry or blaming you for his unhappiness, remember this. He is trying to cope with his internal "demons" by utilizing defense mechanisms to protect his own self-image; to keep him safe from the rawness of the true feelings or the possible shattering of the self-image. This is the reason why most people turn the image of their spouse completely around after the BD happens. Before, they could love this person for years; after, the spouse is a monster who deserves a bad life.
The sad part? Projection happens quite often as seen in this board. People expect spouses to bring the happiness when in fact true happiness is gained by consistent growth of oneself.
I read your story through and as a word of encouragement, you seem to be a really strong person. Whether this goes as you currently want it or not, you will learn a lot from this and will eventually find your place with or without him. I admire your strength in studying considering the factors you have in your life currently. Remember, baby steps and it takes time - a lot more than you think. Good luck for the future
In my thirties, BDd 2017, divorced 2 young kids new relationship
