Hi There
I am sorry to hear about your current difficulties with your FTO. It’s not an easy situation to be in. From reading your post it sounds that you feel quite intimidated by this instructor, which is perfectly understandable given the situation.
Firstly don't approach your instructor go straight over his head to management! In your experience in the school do you know of a senior member of staff or management with a bit of clout? Someone in seniority that this guy may have clashed with in the past then all the better. At least make sure that the person you complain to is a member of management and senior to your instructor.
You also need to protect your interests. Insist on a new instructor immediately. Demanding might not get you anywhere! The best approach is to be mature and respectful to the person(s) you complain to but it is important that you are assertive and very firm in what you say! Also if you feel confident enough ask the person you make the complaint to, to arrange to meet you and the instructor as there are some questions you may like to address to the instructor. Write the questions down! And ask him in front of the third more senior party. Inform him that the language he uses is far from acceptable and not professional in conduct? Ask why he feels that he has the right to speak to people in such a derogatory manner?
If that gets you no where then you may be left with no option but to return home without completing your training. But that is not the end of the world mate. I am not one to walkout on anything or to quit on anything. But one thing I have learned in life is that you should never allow anyone to speak to you in a manner that is degrading. If they do DO NOT allow it to reflect on you or your confidence!
If you have paid everything up front then try to resolve the situation. If you have not then the best thing to do may be to call it quits. But if that is your only option then make sure you complain about your instructor before leaving and put it all in writing to his superiors and the owner/proprietor/CEO of this instructors conduct. Inform them that this is how they are being represented by a member of their staff.
Finally what goes around comes around. Someone with attitude like his may find it difficult to make it as a professional pilot, who would want to be stuck in a flight deck with someone afflicted with a personality as bad as his? If he has been instructing for a long time maybe he should work on improving him manner, it might help him gain employment as a Pilot for an airline. Presuming that is him goal!
Edited to add this
After all is said and done and once you have made your complaints it would do your confidence to world of good to say whats on your mind directly to the instructor. Don't get drawn into a tit for tat argument with him but point out some of his personal home truths that he may not like to hear, along the lines of the paragraph above. Providing you dont feel physically threatened by this guy!
Good luck mate hope it works out.