What programming language should I learn?

Hear me out. I'm a UX designer by trade; while not a developer, I do understand software and technology very well. I spend a lot of time testing and tinkering with ideas by trying to hack them together the best I can. My goal is to build a small but real feeling version of my idea to understand and test if there's actually value. I continually hit the wall or spend hours getting caught up on something trivial (I understand this is part of the learning process). Like for most people, time is an issue for me and I'm really looking for something to help me prototype quickly. I consider Ruby and Python too big for that (am I wrong)? What should I focus on, a Javascript framework, just jQuery, something like Haskell, etc.? 

First, it's admirable to want to learn something new.  Programming is a tough discipline to master.  In spite of every startup CEO telling you they themselves coded their launch project, and that you should just learn to code it all yourself, this is not a practical approach.  The statistic we don't have is how many of those startups continue to be a success without having their code re-written by competent programmers.