When a person feels numb toward everything else, she is not in a good position to make life-altering decisions. She also probably needs to be in treatment. I do not think that you have a good treatment team, because you state that you have BPD and yet you are only 18. PD's are not dx'd prior to age 18, so right now your treatment providers should be considering BPD with some degree of doubt.

Numbness can be from PTSD as well, and from seasonal depression during short days, and from BPD, and many other things.

I would recommend that you take therapy and diagnosis seriously and ride it out with the guy, not making any knee jerk movements, not because leaving him now would kill him or you or both, but simply because your decision-making capacity is now seriously impaired. If you are OK with him when you see him but forget about him when you don't, it not the end of the world. That you feel numb all over is much more worrisome.