"The crazy thing is that after all we've been through I can't shake that "what if they're right" feeling"
Salvation is through faith not the GB. Relax. They are not right.
Try reading Romans, Ephesians and Galatians the same way you would read a news paper.
Paul's message is clear.
Romans 5:1 Therefore since we are justified by faith we have peace with God through Christ
Romans 8:1 There is therefore now no condemnation for those in Christ
Ephesians 1:13 In him you also, who have heard the word of truth, the gospel of your salvation, and have believed in him, were sealed with the promised Holy Spirit, which is the guarantee of our [your] inheritance until we acquire possession of it....
Galatians 3:23-29 Before this faith came, we were held prisoners by the law, locked up until faith should be revealed. 24So the law was put in charge to lead us to Christ that we might be justified by faith. 25Now that faith has come, we are no longer under the supervision of the law. 26You are all sons of God through faith in Christ Jesus, 27for all of you who were baptized into Christ have clothed yourselves with Christ. 28There is neither Jew nor Greek, slave nor free, male nor female, for you are all one in Christ Jesus. 29If you belong to Christ, then you are Abraham's seed, and heirs according to the promise.
Examples of this message are all over the New Testament. Salvation, for the believer, is assured. We should be the most relaxed people on earth.
Peace