Dear tstesen
I am in the same industry for last 10 years and I feel precisely the same as you do now. I still do not have a proper solution for this problem. But what I have been working on since I realised that I am properly stuck in disliking my current job is to create time and space to stop working altogether, give lots of time to myself and figure out what I really want in life. If you can't afford stopping work completely, perhaps you want to drop those clients that give you the most trouble (that is a good step to take regardless) and raise prices somewhat for others. These two steps will leave you with good clients who actually value your work. That alone can be a good step towards feeling better about your job already and give you spare time to do things that inspire you.
I also know that if I don't have a vacation to some nice place at least once every half year, my creative resources get depleted and I can't really make any fresh work. So if you haven't had any vacations, perhaps it is a good time to make one.
In general what I know about people who work in this industry and what also applies to myself is that we have 2 problems in common:
1. we tend to leave too little "white space" for ourselves and
2. we do so much work for others that at some point we get stuck with the question of what use our input is to the world or to the larger picture (sorry, I can't find a better way to say this).
The white space part is solved by planning and eliminating stuff that gives too little return, so it is quite simple. But I still have not found an answer for the second question.. will keep working on that
