Keep on with it. Speed bumps happen, the best thing is to learn from them. I admire your ability with languages it’s something I really wish I could devote more time to.
People offer obvious advice because they want to help, even if it’s not actually helpful. The trick is handling such responses gracefully which isn’t easy sometimes. They haven’t got your experience or perspective - unlike your prof who is proof that what you want is possible and realistic.
Remember you also have good days. It’s hard work and it’s rewarding. Good luck.