pull (oneself) up by the bootstraps
To put forth effort to improve one's life or circumstances, rather than relying on others. After I declared bankruptcy, I had to pull myself up by the bootstraps and rebuild my financial standing. I know you're heartbroken by this breakup, but you just have to pull yourself up by the bootstraps and get back out there into the dating scene.
pull oneself up by the bootstraps
Succeed by one's own efforts, as in She was homeless for nearly two years, but she managed to pull herself up by the bootstraps. This expression alludes to pulling on high boots by means of the straps or loops attached to them at the top. [Early 1900s]