Have you ever felt anxious/ashamed about yourself when studying with other people, because of your learning disability?

I am a dyscalculic but I think my fears are common between many people with learning disabilities in general.

I study Biology at University and often I ask other students to meet and do exercises together (especially for Math, Statistics and Physics which are a lot numerical)... But when we finally meet, I realize how useless I am and I know that everybody around me are thinking that I am only making them waste time.

If I don't understand something, somebody has to explain it slowly and multiple times before I catch the concept and in the meantime others in the group have to stop for a while. I feel like I am slowing other people down and that they should just give up and live me behind, like I was a burden for them...

It happened to me two times to star crying (the first time when I was with a group of students, the second during a lesson) because I couldn't keep up with others and felt stupid. How do you deal with these situations?