If you have a good friend, who is helping you in your practice, and continuously helps you in your practice, great! Wonderful. Thank them a lot and listen to them some more. If their standard is a bit higher than yours, great, you've got a direction to move towards. That is wonderful, don't worry about that. You don't have to worry that you are not up there yet. That would be developing self-hatred, which is more what the second part of this question is about. But, in regard to having a good spiritual friend, what we call a Kalyanamitta in the Pali language, wonderful. We all need one. So if you've got one, that's great. And if you can gauge your own practice by looking at them and comparing, and seeing where your weakness are, as well as where your strengths are, and then being able to decrease or increase them with the help of your good friend, that's wonderful, that's very good.
So to the question "What should I do?" there is no reason to do anything, what you have is wonderful, keep it. Respect the person, help them out as much as you can on other levels. If they are helping you with your mental well-being, perhaps, you can help them in other ways.
To the question "How do I grow in my own confidence?" there is no reason why you shouldn't grow in your own confidence at the same time. Because that person, hopefully has a sense of confidence in themselves, and therefore you can try to copy that as well, just like everything else you're trying to improve yourself on, based on what you see in your friend. Basically everything that we are teaching will help you to develop confidence.
Being able to forgive yourself is one very important thing. There is a meditation on that specifically later in the retreat. Forgiveness ties in with having compassion for ourselves. If you remember the long Compassion/Lovingkindness meditation that I do each retreat, I talked about thinking of ourselves when we were six years old. Get we have compassion for that little kid who didn't know everything, who made mistakes? How about when you were ten years old, fifteen years old, last year, yesterday, can we have compassion for that person who made mistakes? Who didn't know any better? In having compassion for who we were in the past, we can take the next step to forgiveness for that person. We are accepting that yes, we made mistakes. Yes, we didn't know better. But if we see that we have changed, we are different, we are able to forgive who we were. So a lot of the development of confidence in yourself, hinges on the development of compassion for yourself as well. Then you gain more strength.
Confidence is also greatly aided by reflecting on your good actions, your good past Kamma. If you think of all the good things you've done, don't you feel strong? If you focus too much on the negativities you're going to feel under confident. So we have to focus a lot on the good, positive things that we've done. Now, if you haven't done enough good, positive things, so that you can't reflect enough to get that confidence, then do more! Do more good actions, so you have more to reflect on.