I know not how to aid you, save in the assurance of one of mature age, and much severe experience, that you can not fail, if you resolutely determine, that you will not.
The traits the word 'childish' addresses are seen so often in adults that we should abolish this age-discriminatory word when it comes to criticizing behavior associated with irresponsibility and irrational thinking.
There are things which some people never attempt during their whole lives, but one of these is not poetry. Poetry attacks all human beings sooner or later, and, like the measles, is mild or violent according to the age of the sufferer.
In this day of wonders no one will say that a thing or an idea is worthless because it is new. To say it is impossible because it is difficult is again not in consonance with the spirit of the age. Things undreamt of are daily being seen, the impossible is ever becoming possible.