your standing is not fragile

Paul's sentence has an order to it, and the order is the whole point. Justified by faith - therefore peace with God - therefore access into this grace, and then the phrase that settles it: "this grace in which we stand."
Heiser's framing of this passage is that works are the result, not the cause. Faith and works validate genuine faith; they do not generate the standing. So the standing is not something your performance holds up. It was established by a verdict already passed, which is why Paul can move straight from it to rejoicing in sufferings without the argument collapsing.
Scripture links:
- Romans 5:1-2 - "Therefore, since we have been justified by faith, we have peace with God through our Lord Jesus Christ. Through him we have also obtained access by faith into this grace in which we stand."
- Romans 5:8 - "God shows his love for us in that while we were still sinners, Christ died for us."
Your footing was not laid by you. A bad week cannot take it up.