Ding,
that's a pretty disheartening tale. But, if you really want to do this, you'll pick yourself up and go on. There are thankfully few instructors like the one you describe.
I entirely understand the bad feelings engendered if someone is honestly told that they aren't up to a professional career in flying; there are more that can't do it than can, inevitably. However, there's never any excuse for victimisation, bad-mouthing or other intinidatory tactics.
A last point; sometimes instructors make mistakes. One of my students had a real problem when flying with me, to the extent that I suggested that she would never make it through professional training (her history with other instructors was similar). To make a real fool of me, she persevered and is now a Captain in a four-engined long-range transport. She's also a good mate, and is sometime found in the more disreputable parts of Pprune!