Thank you for your question.
If you have a documented learning disability then you are entitled to protection under the Americans with Disabilities Act from discrimination
in employment. If your disability is affecting your work or preventing you from being able to do the tasks assigned, you have the right to request an accommodation from your employer that will allow you to continue working in consideration of your disability.
In your case, the employer has asked that you request the accommodation. This is the standard procedure that a person with a disability under the ADA
must follow in an employment situation. Your employer has not actually discriminated against you, they are asking you to specify what you need from them in order to be able to comply with the ADA. If you do not turn over an accommodation request, they will be entitled to take action and terminate you on performance grounds.
So, in order to prevent this from happening, you need to give them the accommodation request they are asking for. This means essentially that you need to tell them that you need to tell them in a written document that you need to have a lighter work load in order that you may complete your tasks without making mistakes.
Did they give you a form to use for the accommodation request?
Do you have a doctor you can go to to ask them for documentation of your learning disability?