As a beginner, here is my commentary on your advice:
Dejected solipsism is trying to live, dingus. I'm not saying stop trying to solve your supposed problems. I'm saying that trying or not-trying anything is trying to live. And that is the greatest mistake in life. Sitting in your underwear because you're sad you aren't happy is as much trying to live as taking the dog for a walk because your wife just gave you a blowjob. Is that something people do? I wouldn't know.
Go ahead, stop trying to solve your supposed problems. You're sure to learn something from that, right? Or is that obviously bad advice?
But if you do stop trying to solve your problems, what do you do? Do you contemplate the many problems you supposedly have, do you ask yourself over and over again why you don't stand up and do "what needs to be done." Or do you just sit, not solving problems?
Anyway. Mumon gave a practical and user-friendly guide, it's called Mu. Which means No. So basically, you just find whatever question you've got on your mind right now like "What is the meaning to life?" and then use "Mu" on every answer that arises. Your mind will keep generating answers for you to "Mu" until it runs out of options and realizes that the question is dumb as all hell.
Or skip ahead and, when a question arises, just answer mu. Do you believe that answer? Or is mu just a mantra?
Once your brain has recognized the question is dumb as all hell, it'll stop asking. Then you can move onto the next question you have, like. "What is truth?" or something. Then you just keep doing that, finding your questions and Mu'ing them until you get down to lets say, "What is the different between 'is' and 'is not', 'self' and 'other?" and when that question is gone so is your conception of anything/everything, and the self/environment to perceive it or be contained in. Tada you're enlightened. Enjoy the user-friendly guide.
I would add, notice the way the answer 'Mu' becomes habituated. Do this carefully and you will start to see the 'Mu' arise in response to all conceptualizations, seemingly independent of you. Thought is like this. It is habitual and cyclical, which gives it the illusion of permanence. Now do you really want this 'Mu' habit cluttering up your mind?
Mumon called it 'great doubt' because you're doubting everything that you've ever possibly thought is real.
Descartes goes through this very intellectual process in the first meditation and comes away with "I think therefore I am." Mu.
It works! You can do it all the time. And here's the secret: doubting something is not a reason to take any action on it. Just because you're questioning why you live doesn't mean you should or shouldn't try and live.
Neither should nor shouldn't. No easy answers here. I bet you find you do it anyway. Whatever it is your doing.
Doubting the reality of the question is completely seperate from whatever you are currently thinking about it! if you're thinking that questioning something means you cant live out your life, that's your own deception. Quit it! Go do something productive.
What we are talking about here isn't enlightenment, its the process of cultivation. You don't have to pull the weeds from your garden, but don't cry to me about weeds choking your petunias.
Work while you Mu, live while you Mu, until you stop living.
Good luck not following this advice!
tl;dr, tl;dr