You are so wrong about your position about the deal. Your reasoning is flawed and your source of information is distorted.
Here is why:
1) The sanctions on Iran has only hurt the people, not the government. Moreover, the sanctions have neither hurt the fundamentalists nor the Revolutionary guard, nor has it slowed the nuclear program. As a wise politician your aim should be to connect and embrace the people, the governments will follow. US and the rest of the World should embrace Iran’s moderates with their move towards dialogue and normalization, otherwise they will lose to the fundamentalists.
In general Diplomacy must always be chosen over sending troops and WAR. I hope you and Congress realizes that and respects human lives.
2) France, UK, Russia, China, Germany and EU have approved the deal and have no intentions of backing out. By congress not approving the deal will simply isolate US. However, more importantly US will be distancing itself from the moderates (which have the majority support) and hence the people of Iran. That would be a BIG BIG mistake on your part
3) The sanction could not have stopped Irans’ ability to build a weapon. If they wanted they could have built it long time ago, with Netanyahu’s first suspicion. See http://www.csmonitor.com/World/Middle-East/2011/1108/Imminent-Iran-nuclear-threat-A-timeline-of-warnings-since-1979/Israel-paints-Iran-as-Enemy-No.-1-1992, where back in 1992 Netanyahu gave Iran till 1995–1998 to have Nuclear weapon!!!!!! What happened? It is Iran’s religious belief to be against nuclear weapons. Please research this and be informed. It has only hurt the Iranian people! It is really for the push towards moderation led by the Rohani’s government, (elected by Iranians and as a reaction to Ahmadinejad’s hardline stance) that Iran has been forthcoming to the negotiation table. You should consider this as an opportunity for peace and moderation.
4) The Iran Nuclear deal is the best ever deal created in preventing anyone from producing nuclear weapons. You wouldn’t be able to match that deal. Show if you can, one deal better!