Struggling with BPD in a Long Distance Relationship

so I have bpd and my long distance boyfriend hasn’t really been the most supportive person in the world when it comes to me lashing out. I’ve been going to therapy for almost a year now, and whenever we are together in person he is so supportive but whenever we argue long distance he makes me feel like such a burden. we got in an argument a week ago and haven’t spoken since. I lashed out at him for something small, he forgave me, and when I asked for reassurance he just told me that he was so sick of this cycle and he can’t take it anymore. he wants to talk soon and I’m scared he’s going to end it over something that I’ve been working sooo hard to control and fix. anyone been through anything like this, and how did you solve the problem with your s/o?