Please don't think I'm trying to be insensitive or a ***hole, but welcome to the world of flying. Since I don't know how much you let it slow down there isn't anyway to know if you were in the normal performance window for that plane. My guess would be that you were landing it like your first plane (a trainer I assume) and it stalled before you trainer did. Sounds like a normal situation. All of us have to adjust our flying styles to the planes we fly. I don't land my Hog Bipe biplane the same way that I land my Balsa USA Thunderbug. You have to learn to fly the plane. Now that you know what it's going to you know how to fly it to avoid that situation. Get it on the ground before it stalls.

Now, with all that said. There could be something wrong with the plane. Get your instructor, or some of the more experienced pilots at your field, to look over the plane to see if there is anything seriously wrong with it. Check the balance, both CG and lateral balance, check for washout in the wings, check for warped wings. If all that checks out and they don't find anything wrong with it, learn to fly it. If they do find something wrong with it you'll be able to fix it.

Just my .02 cents worth.