I met a girl at one of our church's small groups that I started going to when I was new to the church. Prayer requests were a part of it, and one of hers was that she was having side effects from a new medication she was taking for anxiety. I struggle with clinical anxiety as well, and since she had been particularly welcoming and kind to me, I came to her for support. Since then, we've become great friends (She knows more about me than any of my other friends.) One of those being that I have trouble articulating my thoughts, and that that makes prayer a struggle for me too. We were talking on Facebook last night, and this one of the messages I sent her:
"I spent some time praying, but I got stuck when it came to for myself specifically. Obviously I know what my struggles are, but not how to address them in prayer?
Intelligence comes in many forms. If you struggle with one area, such as articulating your thoughts, that doesn't mean you are stupid. It simply means that is one aspect that you struggle with. But, really, you don't show any signs of making yourself clear. Nothing in this post indicates you are particularly bad in getting your thoughts across. I suspect is has more to do with how you're viewing yourself, and less to do with it being a real problem.
Also, if you tend to talk about yourself by using insults often this can turn others off. Rather than saying 'i'm stupid' try just asking your question more simply. 'Hey, i'm not really sure how to pray about this, would you mind if i ask how you pray about it?'. Something similar to that.
But really, think about what you're asking. You approached this girl telling her 'i'm stupid', now you're asking us how you can make her think you're not stupid. Try by not saying it yourself. If you don't respect yourself, others will not respect you either.
In reality, though, you have no evidence that she even thinks that. All you know right now is she hasn't responded,but you don't know why. Give it some time and maybe she'll respond and offer an explanation. Or give her a day or two and then message her again and ask if everythings ok. That you were worried since about her since she hasn't responded to your question. Maybe something is going on in her life that is making it hard for her to respond. You never know. Don't be so quick to assume you know what people are thinking.