You know who you are, and what is in your heart, and what you're willing to do. No mere opinion from someone else has the power to hold you back.
Pay attention to what others say if you think it could be of use. Seek to understand and to make yourself understood as well as you possibly can. Yet always keep in mind that the person who knows most about you is you. You know what you can do, and you know why you're doing it, even if no one else understands.
The hurtful, limiting comments say more about the people who make those comments than they say about you. Whatever they may say, you know who you are. Move on confidently forward with the best that you can be.