Analysis:

Not easy to learn.

I have a classmate who plays the guitar very well. I began to learn erhu in the first grade, and now I am in the third grade, and the progress is very slow.

Regardless of academic factors, if you have a good teacher and insist on practicing effectively for more than 4 hours every day, it will be almost the same.

Erhu has little to do with playing the piano except by hand.

The basic movements of erhu are much more complicated to learn than piano, that is, it takes at least one week to practice playing empty strings, and then it will take a long time to practice.

Your advantage now lies in your left hand, and your stamina for learning erhu will be greater than others. But basically speaking, it takes a lot of time to learn erhu, so we should take it slowly and steadily. I don't know if you are studying erhu for the exam. If so, I suggest you learn dulcimer, flute and sheng, which is faster.

Besides, my situation is the opposite of yours. I began to learn erhu in the second grade, and I have been studying in the second grade. I have learned the piano now for the composition test. I think it is better to cultivate the ability of piano hands to cooperate, which is good for you to learn erhu.