No matter what you decide to build next, it will be important to get some hands-on, in the room guidance from an experienced builder. The finest precarved, pre-inletted kit still requires considerable skills and the right tools, expertly sharpened, etc. From here we cannot tell how your chisels are cutting, whether you're using a rasp the right way, whether the motions you use to shape a stock are optimal for achieving the desired result. Hands on, pointing, demonstrating, watching, correcting guidance can get anyone to a higher level much faster than advice online.
It doesn't matter how much you spend, a fine kit is no guarantee. Enough wood is purposely left to make for a clubby gun if the builder does not understand shaping and architecture. I often see lock panels on a kit assembled by an inexperienced maker left exactly as they came from the supplier, for example, when it is clear the precarve lock panels were left oversize deliberately to allow the maker to vary the lock panels considerably. But the supplier never intended the panel be left as supplied. So a fine kit still requires a good eye and a design plan. It's a big mistake to think someone can learn to build longrifles exclusively with online advice and books and DVDs as their instructors. Yes, a functional gun can be made that way. Even when a plain approach is taken (no carving, no engraving, maybe even no moldings) the same $800 plus kit can be turned into a $350 rifle or a $1800 rifle depending on how it is made. Every builder gets better with time and experience. Most of the time that experience is seasoned with some measure of failure and disappointment resulting from going ahead without hands-on instruction and feedback, and not honing skills till they are excellent before diving in.
Folks know they cannot play a saxophone w/o practicing and without a teacher. The same is true of building a longrifle. The fella who picks up the sax can make sounds but not music in the beginning.