Thought from left field:

Have you considered starting a cough lifestyle business, or less-controversially, working as a contractor for <20 hours/week?

The idea would be to earn a decent living from a part-time source, and spend the rest of your time learning new languages, tools, etc. In other words, disconnect your dreams from your job. If jobs aren't fulfilling you, change your definition of "job" to "something that pays the bills."