How do I find out if I have a learning disability?

Hello everyone. :)

I’m 18 years old and I’m currently in the process of getting my GED. I’ve been enrolled in GED classes for a few weeks and going to take the test very soon. I’m very nervous about taking the test, especially the math section because I’ve struggled with math my whole entire life. I’m even falling behind during the classes and I feel so lost. I also found out that I have a 5th grade math level. When I first joined the classes, we had to take a test to determine where we were at with basic subjects and I must have done horrible on the math section because the teacher told me I’m at a 5th grade math level.

Anyway, I think that I have a learning disability and I would like to know if I do so that I can properly take the test when it’s time and receive all the help I might need. When I was still in school, I remember something called math sld being mentioned, but I know absolutely nothing about and I’m not sure if I’m classified or not. I’ve been googling math sld the past few days and finding out more about it but I still don’t know that much.

Can anyone please tell me how to find out whether or not I have a learning disability? I dropped out of school last May because I got left back twice and I didn’t want to wait until I was 20 years old to graduate. Can I just go to my old high school and ask them if I have a learning disability or for proof that I have one? I have absolutely no idea where to start looking to find out if I have a disability and any help would be greatly appreciated. Thank you!