>>10809881I'm not worried about it at all. Heaven is, essentially, union with God. Heaven is the ultimate end and fulfillment of the deepest human longings, the state of supreme, definitive happiness. This is because God, who is esse ipsum subsistens, the ground of all being, gave us being to know and love him. And because choices are all ultimately made in light of some good, I don't see how one who has experienced the ultimate good of union with God would choose some lesser, perceived, good.
Additionally, keep in mind that eternal life, heaven, and union with God are all basically the same thing. When we are alive and can change our will over time, we have a chance to choose God or not, but when we die, our will becomes "fixed" in the sense that we have already made our choice. Thus, being in eternity, the idea of changing ones will - wanting God and eternal life with him one moment while rejecting him and suffering eternal death later - simply does not make sense
Also, don't worry about making God angry by asking this. To sin is a conscious act of the will. You're just having anxious thoughts.
I hope this helps ease your mind a bit and I wish you all the best. God bless.