Getting "comfortable" is all relative, and every patient/new team is a learning experience. Look at it that way, and don't be too hard on yourself when you screw up. From now on, every time you struggle with any part of a presentation, ask the preceptor for advice about how to improve, and try to do what s/he tells you. The next presentation will go better if you make a concerted effort to do better. Especially when you work with the same preceptor for a while, the improvement will be clear to everyone, including you.
When I was near the end of my third year, I did a presentation that was pretty awful. It was my first day on that service, and I didn't present the A/P the way the attending wanted. Not only that, but I didn't really understand what she wanted at first. So she and the resident prompted me as I struggled through, and then I asked them to let me present the A/P again, which went much better the second time. There was also a first year student there shadowing, and I made a comment after rounds to her about how I had really screwed up that presentation. (Paradoxically, I felt much more embarrassed about the first year seeing me struggle than my team.) She looked at me, and said, "I was thinking how awesome your presentation was, and I hope I'll be able to present like that some day."
That really put things in perspective for me. We're students, and if we knew how to do everything a physician does already, we wouldn't have to go to medical school. "Everything" includes presenting patients. You'll often feel like you could have presented better, but as long as you are honestly trying to incorporate the feedback you receive, you will present better than you did the last time. As you start to improve at presenting, you'll keep setting the bar higher, which is a good thing because you'll keep improving. The important thing is to be open to the feedback you receive from your preceptors, and if you don't get it spontaneously from them, *ask* for it.
Hope this helps, and best of luck to you.