Knotwilg wrote:
According to them, my accent is flawless
As my English teacher used to say: Flattery will get you everywhere.

Polish pronunciation is also difficult for some similar reasons: Like Chinese, there are several sh and ch sounds and although they don't have characters, they do use an awful lot of z's...
Regarding the difficulty of Polish and Chinese, the
FSI (Foreign Service Institute) lists Chinese as one of the hardest and Polish as one of the second hardest languages for English speakers to learn. It is interesting to note however that opinions do indeed differ widely.
Here is a well known rant by a student/professor of Chinese, David Moser, about how hard Chinese is, and
here is a rebuttal by Benny Lewis, the creator of Fluent in 3 Months. I concur with Gotraskhalana that having a positive attitude is beneficial, and that imaginary demons can indeed inflict harm, yet it seems prudent to acknowledge a difficulty if it actually exists. Benny Lewis did in fact manage to learn a good deal of Chinese in a short amount of time, but I think the pessimest Moser might be better prepared for the long haul.
Regarding the OP, who might still be interested in the OT, I have heard of a number of people who have achieved dan ranks in a year or so. None of them afaik were over 30. Some may say that this is due to outer constraints such as job and family and that may be true, but University can be a bear too and I also know that some of us older folks somehow manage to invest a pretty hefty amount of time into their go...