It may be that your situation and priorities do indeed restrict you from making the time investment to get good at whiteboarding and FAANG-style interview practice. It doesn't necessarily follow that you're stuck hard doing what you are now.
If you're using the term "trapped" to describe where you work, I'm inferring that you want a change. It's hard to get specific without knowing all your priorities, details, and life choices, but it's almost certainly worth taking a step back and evaluating if there's ways to get what you need by an alternative path that doesn't involve slotting yourself into a process that's optimized for smart single twentysomethings.
If you're using the term "trapped" to describe where you work, I'm inferring that you want a change. It's hard to get specific without knowing all your priorities, details, and life choices, but it's almost certainly worth taking a step back and evaluating if there's ways to get what you need by an alternative path that doesn't involve slotting yourself into a process that's optimized for smart single twentysomethings.