I'm ready to be downvoted for this, but if you can't solve a problem in 15-20 minutes, just look at the solution, understand it, and memorize it. The more problems you work on the better your pattern recognition will get, and it'll be easier to solve related problems. Unless you're a genius programmer, I seriously doubt most normal people can easily and flawlessly answer these stupid questions within 15 minutes in an interview setting.
Also keep in mind that the vast majority of interviewers will tell you that they're looking for a good thought process as opposed to the correct solution, but they're 100% full of shit so don't believe what they say. There are hundreds of engineers who have already memorized 300+ leetcode problems and WILL write correct and bug-free code in an interview setting, and they will get the job no matter how good your "thought process" is. However, there are SOME companies that care about thought process, and those are the ones you have to look for. Unfortunately I haven't found out how to determine which companies actually do that, but typically they're start-ups. This only applies if you're in the Bay Area, however. I can't comment on what it's like outside of California.
I feel like nobody in the thread truly read your original post. You asked for alternative career options because you can't solve leetcode problems and that's absolutely ridiculous. You can absolutely get hired as a software engineer, you just have to play the game. Keep leetcoding and you'll eventually crack an interview. It's just a numbers game. Good luck!