Hi and

Having little support, a partner with a PD, a stressful academic journey, and your own sensitivities, is a lot for anyone to handle -- so we're glad you reached out to us here.
Many members also experience the blame and rage that you have faced, and it can be difficult when there is a small grain of truth underneath their inappropriate, out-of-proportion, hurtful outbursts.
Finding your own healthy sense of self, with the ability to determine what you are responsible for and what you aren't responsible for, will be important for staying in this relationship.
For example, conflict over timeliness can be a normal conflict for couples. Many couples negotiate this challenge and have different values and priorities about being on time.
When BPD is in the mix, though, the emotions and reactions around it can be cranked up to an 11.
This can make us want to go to one (or both!) of two extremes: either giving in/capitulating/blaming ourselves entirely, or being really defensive/blaming our partner/insisting it's not our fault and is all their problem. Losing a balanced view of the situation is common in BPD relationships, and finding balance again is important. It's
not all your fault, and it's not all his fault -- you both contribute, though in different ways and to different degrees, and you can only be responsible for your contribution to conflict, not his.
It sounds like you've tended towards taking the blame in these situations:
Giving into his demands, trying to "correct" myself for any behavior which he thinks is "unhealthy" has left me very drained and extremely depressed and burnt out.
which, like you said, doesn't help you. And, it doesn't help him, and it doesn't help your relationship. After all, if you taking the blame were effective, things should've been better by now, right?
It would be very helpful if you can share the strategies you use to combat the blame games and to maintain/regain your own identity. A recent example is: extreme rage and shouting at me because i was 15mins late. He is very punctual person. So the shouting goes like "you do this repeatedly, two years back too you were late on so and so date, you have no respect for me, I have no value, my time has no value, so i will move out,i will pack all my stuff next week and move out" .
Where does he rage and shout at you? At home? In the car? In public? Elsewhere?
How long does it usually last?
What have you typically done in the past?
...
cynp touches on an important point here:
Many times they will yell themselves out and almsot "reset."
There can come a time during a pwBPD's dysregulation where there's nothing we can say or actively do to improve the situation. There's no magic wand to wave, or "secret skill", or "powerful tool". There is the realization that we don't control the pwBPD's dysregulation and that sometimes our presence is triggering and makes things worse, and they need to practice self-soothing.
A big thing to consider is -- it may be better (less damaging) to the relationship for you not to be there to hear what the pwBPD is saying while dysregulated.