I am in a bad place with my current job and I am struggling to find a solution. I ostensibly have one year experience with software development at a reputable company, but that belies the truth, which is that my experience is almost worthless. Although my job title is software developer, in reality, I have mostly been assigned support activities for the better part of a year. Instead of building my skills, they largely have been atrophying for some time. I have been gaining other skills, but they do not seem relevant for the software development interview process.
I have spoken to my manager and my manager's manager repeatedly about my concerns, and I was totally blown off. Essentially, my duties will not change, and if they do, it would likely take a year or two to reorganize teams; but as I said, my skills are getting worse, not better. Furthermore, I find the work deeply unfulfilling, as well as not particularly useful for my career goals.
To remedy my lack of skills, I have been doing practice interview problems on my own time, and I intend to increase my own practice and ensure I consistently do it for 1-2 hours a day.
However, I have been doing quite poorly on technical interviews because I have very little solid professional experience (despite my resume suggesting I should have some very good experience). For example, I may get asked a question about a particular aspect of a programming language, but as I have not been using any of them very much, I am often forgetful of the details. I also do not really have the experience to answer the more in depth questions thrown my way.
It also strikes me that working through interview questions alone may not be enough, as it will not prepare me for broader system design questions, or general project experience. For example, an interview question may help me with my algorithms, but it does not help me with my object-oriented design.
I feel I might need to quit so I can practice, learn, and interview full time, but this is obviously tricky because I still need an income.
In short, how can I get myself a different job when I lack the skills to do so?