When you are tirelessly working on something or persisting towards a goal, you may describe it as "grinding away." There are a variety of synonyms that can capture this same sense of persistent effort. One option is "pushing hard," suggesting that you are putting in a significant amount of force and energy in order to achieve your objective. Another term is "slogging," which conveys a sense of struggling and working through difficult conditions. You could also say you are "plowing through" the work, indicating that you are cutting through obstacles and challenges in order to make progress. Overall, these synonyms all suggest that you are dedicated and hardworking in your efforts.