Basically, I would say that what you are suffering from is a kind of mental block syndrome: you think in a procedural/imperative paradigm. All your listed languages operate in that paradigm. It's a very transferable paradigm, as it so happens. I can come up to (some approximation of) speed in an imperative language in under 2 weeks. In order to ship Lisp(Prolog, Haskell...), you
have to break out of that paradigm. I am not condemning you, mind. It is what it is. Rewiring your head is hard, and often doesn't have direct results.
I can, however, ship with Common Lisp, because I've spent on the order of 5 years learning it and writing it most evenings. I am learning Clojure and am preparing to ship a (excruciatingly minor) product with that after only maybe two months of dabbling. This is possible because I've bent my head around into Lisp shapes.
It's also been said that some people have the shape of Lisp in their head, and when they learn Lisp, their heads fit it by nature, and other people don't have that innate meshing. I certainly found Lisp to mesh with my head well.
Oh yes. It can be hard to get started with Common Lisp, just in terms of getting an environment working. I have a tutorial site to help with that(plug plug plug): http://articulate-lisp.com/
