Sounds very stressful! Good luck with everything!
Firstly, with the oral, sometimes it's good to remember that although it's stressful trying to prepare for it, as long as you can formulate sentences with verbs etc. and have a BASIC knowledge of what you are going to speak about you will be okay. I was similar to you, I didn't have much time to prepare for my detailed study, but I just memorised basic things and tried to think of different ways the examiners would ask questions about my topic and that helped me ( I had my oral last week and was extremely stressed about it all).
Also it's good to remember to that the oral, although it counts, it counts less than some sacs you've done through out the year. It's nerve racking, I completely understand! I wasn't sleeping properly leading up to the night of exam. (I should have listened to everyone who told me that before my exam!)
With practicing, I found with my class we would skype, FaceTime each other every night and did a 'mock oral' with each other and helped each other out with words and ideas for other questions until the day of the exam. Also during the week we would practice at lunch together on different days.
Some teachers can be frustrating! I totally understand! Once you have spoken to them about it and they don't listen, it's best to just do things on your own or even better, with your friends or your class, because in the end they, your friends/classmates are the people that you will most likely learn more from!
And remember most people in the state will be feeling very similar to you!
Everything will work out in the end, you just need to keep chipping away at it!! Hope this helps a little bit.
Good luck!