first of all, IB Diploma is a VERY CHALLENGING program. You will have to "fight" a lot with yourself in order to push you to do a lot of work because, it will never be enough... There will be sleepless nights when you will need to stay awake to finish projects, IAs and EE and the next day you will have to attend school... There will be a lot of hard work, without doubt... Unfortunately, there will be many "teachers" not willing to help you, so you will have to figure the things out by yourself. That's pretty much the idea of the IB and the worst are coming during the second year.... :-)
But you know what... speaking of personal experience, life isn't easy either.... there will be times when you would have done everything you possibly could and still not getting any reward for all the hard work.... there will be times when you will have to take your life in your own hands, make decisions, try to achieve your goals, make mistakes and fall... However, you should get up and keep going because nobody else is going to do it for you. Hence, don't you always blame your teachers for not being perfect (of course during these two years i was "tortured" by inefficient teachers... but i figured the things out, I found the solution with or without them!), if you want advices ask them! Furthermore, you can watch videos on youtube (especially those concerning natural sciences!!!) and getting extra info from very interesting sites!
My point is, that you should not always try to escape from the difficult situations just because they are not ideal, they will never be... Honestly, during these 2 years in the IB, i learned more about myself than i have learnt in my life. I learned how to cope with difficult situations, as well as how to deal with myself and push me more in order to study harder and harder... This was a great challenge for me, which I don't regret.
The choice is yours... If you tell yourself : " I am going to do whatever it takes to pass the IB and get into the Uni", then you will achieve your goal! Besides, look how many students pass-suceed the IB every year, it is not something impossible or a program designed for geniuses!
Be committed to your goal, try hard, try harder, do your own research, find and read additional notes, try to have a very deep understanding on the materials you are stu-dying... Because in this run you are alone... :-) Of course you will make mistakes, you will fail, get disappointed by yourself, but if you keep going with your head up, there is no doubt you are going to succeed!
And after all, enjoy this experience, it may be life-changing...!
( Hope I helped... I did not talk about subjects and their difficulty, because the only thing that matters is how committed YOU are to your goal and how willing you are, in order to achieve it... everything else (subjects, grades, teachers) will be fine, from the time you are willing to give it all! )
Best of luck! Feel free to ask more questions!