Hi Mahdi, what you wrote is quite good and is certainly understandable, however, as a native speaker, I would say something like the following:
Thank you very much for your compliments, and everything you're doing for me.
In fact I'm preparing for, either an IELTS or TOEFL test, which I'm planning to take in one or two months at the latest, and I hope I'll get an acceptable grade (or: I hope I'll be able to get an acceptable grade).
Anyway...Good luck with your exam :-)