God’s grace in Titus 2:11 is what equips us and empowers us to say, “No,” to ungodliness. But His grace is also what equips us and empowers us to cease our striving and allow Him to be the One who wills and works within us for His good pleasure. So rest.
You may struggle with so many “what if’s” in your life, but when you come to the cross, you see what it is, and what it is is divinely unfair and amazingly equipping that you are able to walk with grace in this life. So don’t resist.
2Co 12:9 But he said to me, "My grace is sufficient for you, for my power is made perfect in weakness." Therefore I will boast all the more gladly of my weaknesses, so that the power of Christ may rest upon me.