Am I unforgivable?

So I have borderline personality disorder, and sometimes it causes me to do impulsive and self destructive things I don’t want to do and lately I’ve been struggling with a certain sin. And there’s a part of me that knows what I’m doing is wrong and I can feel God trying to pull me away while I’m in the act, but it’s like I can’t even stop myself. And now I feel like I’ve completely ruined my relationship with God and that He won’t forgive me since I continued sinning even after He tried to pull me away from it. I’m just so torn up over this and I can’t tell if what I’ve done is actually unforgivable or if that’s a lie.

I’d really appreciate some external input because this has me spiraling