If you want peace and tranquillity, focus on saying “no” to more things and doing less. Be selective with what you give your time, energy, and money to. Focus on what’s essential. Ask yourself: what makes the most positive impact on your life from a mental, social/relational, spiritual, financial, and physical standpoint? How can you keep doing those things (or if you’re not doing enough of those, how can you do it more often)?
On the flip side, what are the biggest/most negative stressors in your life? What are things that need to be done, but maybe not by you or not right now? How can you eliminate or minimize those?
Lastly, stop feeling like you’re obligated to say yes to everything. If it excites you and is good for you, say yes! If it needs to be done by you, even if it doesn’t excite you, say yes. But if it doesn’t, you can just as easily decide to say no if that’s what you really want to do.