How to start and maintain an after-work project

Question

I work as a full time developer. My workplace, however, is very limiting in the technologies and programming languages I can use. All of the work is done in C++.

It is clear that C++ is rapidly losing (or maybe already lost) its leading position. (please don't flame me, I have years and years of C++ experience, and I love this language, I am merely stating a fact). I have a few ideas for Java/Android projects as well as a project I would like to implement in C#. I see this as a way for me to stay current with the job market's trends and I hope that it will help me find my next job in a more up to date area.

So here's the problem:

My normal workday is 10-11 hours, after finishing with the kids and house chores I get about 1-2.5 hours before I am too tired to think, much less code. At that point I am going to bed frustrated, disappointed with myself for not being able to stick with my plans, and then I wake up the next morning to do it all again.

I have a few hours more during the weekends but clearly I would need to do something different if I want to reach any of my goals.

Is there any way for me to make better use of the time I have? Did any of you guys have a similar problem, and had successfully resolved it?