I completely support your point. Mine was similar. People at high school told me I was stupid. One teaching assistant even told me that i would never amount to anything. So I work hard to prove them wrong.
However I left high school with 3 c. The rest ds and one E- maths.
To many who got 10 gcses with A or B, they still laughed.
I prayed day and night to God. I trusted his guidance. Even though I left school I still needed to prove everyone wrong.
I took one GCSE at a time. I retook gcse science- failed 2nd time. Retook it 3rd time passed with a solid c.
Got into college with 4 GCSEs at c. Took a btec course in health and social care level 3. Achieved a triple distinction star. I wanted to aim higher. To go to university I need 5 gcses a c in English language and maths. I got and d in english and an E in maths. I enrolled on 2 course I one year and retook both subjects. I passed both with solid C.
I applied to study occupational therapy at uni and got in dispite others had better grades than I did. Long story short. I am now an occupational therapist.
Famous quote: "attempt something large enough that failure is highly likely.. unless God steps in". I herd this quote watch a video on YouTube. I praise God for his guidance I my career.
The point is, don't listen to the haters. Build in silence, work your butt off until you get what you need!