After that, will it be a difficult, but possible, problem?

Do the math yourself to calculate your odds. Only one of the 7 Millennium Prize Problems have been solved so far, and that by a person widely considered a math genius since his high-school days at one of the best math-oriented schools in Russia and possibly the world at the time. And he was lucky that most of the scaffolding for the Poincaré conjecture happened to be in place already.

So, your odds are pretty bad, and if you don't set a smaller sub-goal, you will likely end up burned out and disappointed. Or worse, come up with a broken proof and bitterly defend it against others "who don't understand the math as well as you do" till your dying days. It's been known to happen.

Sorry to rain on your parade.