Is it possible to correct your vision no matter how nearsighted?

Near sighted. Yes nearsightedness or myopia for the most part is fully corrected. If retinal changes occur as a result of the progressive myopia the the vision may then not be fully corrected.
There are limits. Most who are nearsighted feel they are far worse than we as eye doctors actually consider them to be. There are limits to corrections like LASIK and some are doing lens exchanges for higher myopes. See your ophthalmologist to see what category you fall into.