Three thoughts.

First, evaluate your broader activities, and see where you have the right balance of big projects and small ones. If you're unsatisfied with the balance, do more big projects.

Second, explore collaborations with others. You can often go further together with others, and it would help address the bipolar swings through others providing more stability during down swings. Of course, make sure the "other" in this case is pretty stable.

Third, create a trigger action plan of noticing when you're about to sacrifice projects. Stop and evaluate whether you're doing the right move for your long-term goals.