go it alone

go it alone
(to do something by oneself and without help from other people)
— действовать в одиночку, самостоятельно; справляться самостоятельно

....... Honda has chosen to go it alone rather than set up a joint venture with an American partner. (CALD)
..... After two years as a member of the quartet, Sinatra decided to go it alone. (Cambridge Dictionary of American Idioms)
..... Even countries cannot go it alone in the world today. (Cambridge Dictionary of American Idioms)
.....Do you need help, or will you go it alone? (McGraw-Hill Dictionary of American Idioms and Phrasal Verbs)
.....I think I need a little more experience before I go it alone. (McGraw-Hill Dictionary of American Idioms and Phrasal Verbs)
.....There comes a time in every life when we realize we can't go it alone and seek help. As your therpist for a lifetime, I am available during the times in your life when things get tough and you can't go it alone.
.....Even if the new studies show that many people beat addictions when they reach critical junctures in their lives, psychologists and addiction researchers are more concerned about the people with severe addictions who can’t go it alone.

on one's own
by oneself