I posted a question on StackExchange, but still required assistance from Ellis Lab. They provided me with a solution, that may work for others but doesn't work for me. I posted that solution, but I'm uncertain if I should 'accept' my own answer to a question. Is that a no-no or perfectly fine?
It's definitely OK to answer your own question and then accept your own answer. If none of the answers have a solution to your particular question then I'd say it's preferable to post your own answer and accept it. That way future users encountering your post can benefit and will know that the question is in a more-resolved state.
There are a few rules in place to discourage abuse of this feature: