In English language exams, spelling mistakes can cost you valuable marks. However, the number of marks you might lose for spelling errors will depend on the specific exam board and criteria for grading your paper.
If you suspect that you might have dyslexia, getting a formal diagnosis from a professional, such as an educational psychologist, could be helpful. This could provide you with access to extra support and accommodations that could help you perform to the best of your ability in exams.
To improve your spelling, consider using tools such as spell-checkers or grammar-checkers to help identify errors. You could also try educational apps such as ‘Elevate’. It is also helpful to practice spelling words that you commonly misspell and to ask others to proofread your work to catch any mistakes you may have missed.
Finally, try not to let your struggles with spelling hold you back. You clearly love English and have shown you can achieve good grades despite these challenges. Keep working hard, and don't hesitate to ask for help or accommodations if needed.