I think if I were you I would first try to communicate with the instructor and sort out the problem and what to do about it. If that doesn't work out, then I'd say it's time to change barns. Reason 1
: In a lot of ways, English is really a different bird from Western. Even if you've been riding Western for decades, 2 months in an English saddle probably wouldn't give you much stability over a jump unless you're madly talented and are taking lessons every day. There are a lot of things that are best known before attempting a jump, and not just controlling the horse with legs alone. Reason 2
: Some of the best instructors in the world, no matter what they're teaching, tend to be demanding - they want to see their students progress and succeed. Taking lessons is about learning, not having someone tell you how amazing you are, and good instructors will challenge their students to progress without overhorsing them. Sometimes instructors need their students to have pretty thick skin.
That being said, full-on yelling (not as in trying to get their voice to carry across the arena) isn't helpful or productive. If you feel like the instructor is overestimating your abilities, you need to talk to him/her about it and work out a way for you to gain some confidence.
Sometimes riding can be frustrating, I know. It can be even under the best of conditions. But you can't take that frustration into the barn with you and expect to have a good ride. You need to talk to your instructor, and explain your concerns and what you would like to do. It sounds to me like some good lungeline lessons are in order, and then really hammering in the basics in an English saddle for a year or so before jumping. This should include preliminary stuff like ground poles and cavaletti before true jumps. New concepts for you should ideally be introduced on a schoolmaster, not a "new young horse" who is "headstrong and doesn't listen well."