Heh. I'm right there at the wall with you. Studying and learning is great and I *do* want to pick up my cards to try myself, but actually doing it is another matter.
However, I try not to beat myself up over it because 1) studying is an important part of growth, 2) I can collect a lot of ideas and then see them from a broader perspective when I'm ready, and 3) sometimes life (and things) just get in the way.
1) I like to think of this kind of study as the Hermit, who studies, organizes, and researches information *for himself.* He's not so much an active practioner of the knowledge he finds, but rather he restlessly seeks it and organizes it in preparation for use one day when he steps out into the sun. For now, in the darkness, he shines his light to uncover that which cannot be seen by day.
Likewise, we who are "stuck" in study-mode are not so much unwilling to practice, but rather (at least I personally) feel that we are not yet satisfied with what we've found; we want more. Insofar as we are still collecting and organizing information for later use, I don't think this time of exploration sans practice is a bad thing. Go at your own pace and emerge (break through the wall) when you're ready.
2) I don't know about you, but I'm the sort of person that wants the fullest picture I can have before comfortably starting something. With a system as complex as the Tarot, knowing "everything" is impossible and even knowing one part, like the numerology, decently well takes years of study. Still, before I want to read for others, I want to have a certain amount of confidence in the cards I'm reading. Basic meanings and connecting the cards together in a narrative thus becomes the little goal I've set for myself before I begin reading for others. (For now, I'll stick to Daily Draws, simple 3-Card spreads, and some readings for myself should I have a question.)
Playing off the "collection and organization" theme I mentioned in (1), having a well-rounded grasp of the information is incredibly handy, even if your current understanding is relatively "shallow." The Tarot isn't about individual cards, remember, but rather seeing them together to get a broad-reaching understanding of a specific area. Having spent the time really studying the cards will have given you the wisdom to use all the information you have judiciously, meaning you recognize when something means one thing rather than something else. You might see that the allocation and placement of Suits, Numbers, Major Arcana, Astrological Signs, etc. in the spread point strongly to a particular interpretation, or maybe they're hinting at an undercurrent.
Regardless, spending time at the wall accumulating information will give you more to draw from when you finally do climb over it.
3) Finally, life just gets in the way sometimes. As a full-time grad student, I have school, work, and a (frankly pathetic) social life. There are only 24 hours in a day, and Tarot isn't at the top of my priority list.
Also, as I work on on my reports, books, drafts, and other papers get scattered everywhere. Dishes pile up in the sink and on my table (at least until I get too disgusted with myself and wash them). Stuff literally gets in the way of laying out my Tarot cloth and spreading out some cards.
If this happens to you, as well, take a half day or even a full day to really clean. Put away the things you've left out; wash and put away the dishes; give the table a decent cleaning. It'll clear both the space and your mind. Plus, then there's no excuse not to break out your deck. ^_^
Anyways, I'm sorry for such a long response, but as I feel like we're in the same position, I wanted to offer a different perspective.
So yeah, maybe it’s helpful if you find the root of the problem.