I have some experience encouraging groups who tend to be less sure of their abilities in an academic subject to study that subject and am friends with many people who are much more involved in these efforts, and I know that being confrontational is counterproductive and that you have to be very careful about how you suggest to them that they have a "problem", even if you are telling them that they can overcome that problem. You want to stay positive and show empathy toward their struggles, emphasizing that the struggles are not any failing or inherent shortcoming on their part and are very common.
PS: I know a lot of people who say that they absolutely hate math because they think, for some reason, that they are not good at it. You should consider giving math another try. Math is not just about algebra ...
I like the abrasive comment "you have issues", but it is better to stay positive rather than point fingers. Everyone has issues ;)